Bulletin of the American Physical Society
APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014; Denver, Colorado
Session C1: Poster Session I (14:00  17:00) 
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Room: Exhibit Hall F 

C1.00001: COMPLEX STRUCTERED MATERIALS, INCLUDING GRAPHENE 

C1.00002: Vacancies and Silicon Defects in Silicene Shuang Li Structural defects,which may appear during growth or processing, can be used to tailor the local properties and to achieve new functionalities. Reconstruction of silicene with vacancies formed by up to six missing atoms, rotated defects and adatoms are investigated using a firstprinciples electronicstructure study in the framework of densityfunctional theory. The local structures of defects, their stability and electronic structure are discussed. We found that defects in silicene can induce structural reconstruction, and some of these reconstructions can open a band gap, which is of importance when building nanoelectronic devices. [Preview Abstract] 

C1.00003: Magnetoluminescence study of WS$_{2}$ monolayers T. Scrace, Y. Tsai, B. Barman, L. Schweidenback, A. Petrou, G. Kioseoglou, P. Hawrylak We have studied the photoluminescence (PL) spectra\footnote{W. Zhao, et al., ACS nano, \textbf{7}, 791 (2013).} from WS$_{2}$ monolayers in the 5150 K temperature range in magnetic fields up to 7 tesla applied along the normal to the sample plane. The luminescence was excited by a 488nm linearly polarized laser beam. The PL spectra have two features identified as the neutral ($X)$ and negatively charged ($X^{})$ exciton. At zero magnetic field the $X^{}$ feature has a large (as high as 30\%), laser powerdependent circular polarization, in contrast to the small polarization of $X$that does not depend on laser power. The application of an external magnetic field has a profound effect on the circular polarization of the charged exciton. Its polarization increases by 10\% at 7 tesla for any laserpower while its energy exhibits a small magnetic splitting (2meV at 7 tesla). On the other hand, the emitted circular polarization of the free exciton is not affected by the external magnetic field. [Preview Abstract] 

C1.00004: Anisotropic mechanical properties of graphene: a molecular dynamics study Ming Yu, Anna Zeng, Kevin Zeng The anisotropic mechanical properties of monolayer graphene with different shapes have been studied using an efficient quantum mechanics molecular dynamics scheme based on a semiempirical Hamiltonian (refereed as SCEDLCAO) [PRB 74, 15540; PHYSE 42, 1]. We have found the anisotropic nature of the membrane stress. The stresses along the armchair direction are slightly stronger than that along the zigzag direction, showing strong direction selectivity. The graphene with the rectangular shape could sustain strong load ($i.e$., 20{\%}) in both armchair and zigzag directions. The graphene with the rhombus shape show large difference in the strain direction: it will quickly crack after 18 {\%} of strain in armchair the direction, but slowly destroyed after 20{\%} in the zigzag direction. The obtained 2D Young's modulus at infinitesimal strain and the thirdorder (effective nonlinear) elastic modulus are in good consistent with the experimental observation. [Preview Abstract] 

C1.00005: Local electrical investigations of graphene oxide and its reduction process with atomic force microscopy JiYong Park, Huiseong Jeong, Kyung Moon Lee, Soonil Lee, Y.H. Ahn Graphene oxide (GO) has been foci of active researches as a promising nanomaterial. GO is typically reduced thermally or chemically, resulting in electrical and optical properties similar to those of pristine graphene. Local microscopic investigations of GO and its reduction may complement bulk measurements for better understanding of GO and its reduction process. In this study, we utilized electrostatic force microscopy (EFM) to investigate local electrical properties of GO and its reduction process. Individual GO flakes are deposited onto Silicon oxide/Si substrates. With EFM with high spatial resolution, we could probe local electrical properties to monitor local conductance changes in the individual GO flakes at its pristine state and various stages of reduction process. We can monitor the changes of local conductance inside each GO flake as it reduces with EFM. We found significant inhomogeneities in original GO flakes and investigated evolution in local electrical characteristics of GO with different kinds of reduction processes with EFM. We also correlated the EFM results with electrical transport measurements. [Preview Abstract] 

C1.00006: The anisotropy of Dirac cones in rectangular lattices Mingsu Si, Dezheng Yang, Desheng Xue, Guoping Zhang Thanks to the perfect hexagonal lattice, graphene holds the isotropic Dirac cone. This means the group velocities of charge carriers in the vicinity of Dirac point are isotropic in the momentum space. When the lattice structure varies, Dirac cone will undergo a dramatic change accordingly. This is the case of 6,6,12graphyne. Due to the rectangular lattice, Dirac cones of 6,6,12graphyne are anisotropic. To understand its underlying nature, three twodimensional carbon allotropes with the rectangular lattice are studied using the firstprinciples method. Although the existence of Dirac cone critically depends on the hopping parameters within the unit cell, the anisotropy of Dirac cone is another story. This is because the anisotropy of Dirac cone describes the relation between carrier's velocities, and thus is momentumdependent. It is demonstrated that the anisotropy of Dirac cone can be regarded as an information carrier. This will be the focus of future research. [Preview Abstract] 

C1.00007: Method of obtaining graphene and graphenebased electronic components and circuits with pencil directly on paper Aram Mailian, Manvel Mailian, Gagik Shmavonyan An easy method of obtaining graphene and graphenebased electronic components and circuits by drawing lines or repeatedly rubbing any type of graphite rod along the same path directly on paper and other insulating substrates is suggested. The structure containing rubbedoff layers behaves like a semiconducting material. The surface of the structure demonstrates ordered and oriented character containing few layer graphene. The carrier mobility is anisotropic through the thickness of the structure with the highest value of $\sim$ 10$^{4}$ cm$^{2}$/V$\cdot $sec at the surface. Raman spectra of the structures in the near IR at excitation wavelength of 976 nm (1.27 eV) are registered. The observed phenomenon is universal, does not depend on the material of the substrate and could find a widespread application. For example, the junction between two rubbed off layers with different mobilities exhibits a nonOhmic behavior. IV characteristic of the junction is symmetrically curved with respect to 0 V. The greater is the difference between the carrier mobility, the higher is the curvature. The dynamic accumulation of the carriers in both sides of the junction creates a barrier responsible for nonOhmic behavior. [Preview Abstract] 

C1.00008: Role of Au surface step edge on bottomup growth of atomically precise graphene nanoribbons: Firstprinciples study Tomoaki Kaneko, Nobuo Tajima, Takahisa Ohno The formation of energy gap in graphene can be understood as a critical problem for graphene electronic device application. One of the way to introduce the band gap is use of graphene nanoribbons (GNR). Especially, the bottomup growth can produce high quality and atomically precise armchair GNR, but their length is limited up to few tens nm. For the GNR growth, 10,10$'$dibromo9,9$'$bianthryl (DBBA) precursor molecules polymerize on Au surface at 470 Kelvin and resultant polyanthracene becomes into GNR by surface assisted cyclodehydrogenation at 670 Kelvin. In order to obtain much longer GNR, understanding of the formation of polyanthracene is necessary. In this study, we investigated the adsorption of DBBA, polyanthracene and GNR on Au surfaces by means of firstprinciples calculations using PHASE code. The effect of van der Waals interaction was included by the semiempirical method by Grimme. To discuss the effect of surface morphology, we considered the flat Au(111) and stepped Au(443). We found that DBBA and polyanthracene are stable at the step edges. These results should be an origin of recently reported growth of spacially aligned GNR on Au(887) stepped surfaces. [Preview Abstract] 

C1.00009: Carbon atom reactions in CVD graphene growth on copper surface: A first principles study Nobuo Tajima, Tomoaki Kaneko, Jun Nara, Takahisa Ohno Graphene has attracted considerable research interest due to potential application to future electronic devices. Chemical vapor deposition using copper surface with hydrocarbon source is one of the practical methods to produce graphene. The carbon atom nucleation and cluster growth processes in the CVD reactions have been studied extensively as key steps that control graphene growth behavior. The initial carbon atom bonding process is especially important, since carbon atom nucleation density dominates graphene quality. In the present study, carbon atom dimerizaiton on copper surfaces, the initial process of carbon atom nucleation in CuCVD graphene growth, have been studied with first principles MD simulations. The calculated results suggest that the copper surface almost melts at typical CVD temperature $\sim$ 1000 $^{\circ}$C, and the surface roughening affects the carbonmetal interactions and the energetics of this reaction. Cu(111) and Cu(001) surfaces show different surface roughening behaviors, resulting in different energetics for the reactions on these surfaces. First principles simulation code PHASE (http://www.ciss.iis.utokyo.ac.jp/riss/english/project/device/) was used in these calculations. [Preview Abstract] 

C1.00010: Exceptional ballistic transport in epitaxial graphene nanoribbons Christoph Tegenkamp, Jens Baringhaus, Frederik Edler, Claire Berger, Walt A. de Heer The patterning of graphene into graphene nanoribbons is an essential task for the development of graphene based devices. For such ribbons with a wellordered edge geometry the presence of onedimensional edge states has been predicted. We use a selective graphitization process on SiCmesa structures to produce graphene nanoribbons with a width of 40 nm. The local electronic properties of the ribbons are investigated by means of a 4tip STM. In combination with a SEM, the precise positioning of all four tips on the nanometer range is possible to perform local transport measurements. Furthermore, local tunneling spectroscopy reveals characteristic features of ferromagnetic zigzag graphene nanoribbons. Transport experiments carried out on the very same ribbon show a conductance of $e^2/h$ for a wide temperature range from 30 K up to room temperature and probe spacings between 1~$\mu m$ and 10~$ \mu m$. Description within the Landauer formalism is possible assuming ballistic transport dominated by a single channel. Transportin the second zeroth subband is only detectable for probe spacings smaller than 1~$\mu m$ due to the short localization length of carriers in this subband manifesting in the increase of the conductance to $2e^2/h$ at probe spacings below 200 nm. [Preview Abstract] 

C1.00011: Symmetry breaking of Graphene in the presence of B and N impurities Erika Putz, Jaime Bohorquez, Hansika Sirikumara, Mohammed Alaboodi, Thushari Jayasekera Controlled chemical doping is a promising approach to overcome a major obstacle of applications of graphene in digital electronics; the vanishing bandgap at the Dirac point. Recent experiments suggest that Boron (B) and Nitrogen (N) islands in graphene lattice will induce a sizable gap in its electronic bands. In this presentation, we will discuss interesting symmetry breaking properties that would show zero band gap, even in the presence of impurity atoms. Our findings are consistent with the already reported results, and additional features of the symmetry breaking will be discussed. [Preview Abstract] 

C1.00012: Aggregation modes of bottomup synthesized graphene nanoribbons Mikhail Shekhirev, Timothy Vo, Donna Kunkel, Fran\c{c}ois Orange, Maxime Guinel, Yu Zhao, Alexey Lipatov, Rafal Korlacki, Xiao Zeng, Axel Enders, Alexander Sinitskii Graphene nanoribbons (GNRs) attract a great deal of attention because of their tunable electronic properties. It has been theoretically and experimentally that the band gap in GNRs is inversely proportional to the ribbons' widths. Narrow GNRs with atomically precise edges and large band gaps could be synthesized in bulk quantities by solutionbased chemical methods. However, the properties of bulk and individual GNRs could be different due to aggregation effects. We study aggregation of solutionsynthesized chevronlike GNRs in different conditions and demonstrate two types of GNR assemblies. In a solution, GNRs tend to form $\pi $$\pi $ stacked structures, which was shown experimentally using XRD and different microscopy techniques; these observations were supported by molecular dynamics simulations. But when deposited on a substrate, GNRs selfassemble in very different structures where individual ribbons are attached in a sidebyside fashion. These selfassembled nanostructures, which we refer to as GNR ``nanobelts,'' were observed on different substrates, including polymers, mica and Si/SiO$_{2}$, and could be up several micrometers long. These GNR nanobelts can be visualized by conventional microscopy techniques (AFM, SEM, TEM) and used for fabrication of electronic devices. We will also discuss how different aggregation modes affect electronic and optical properties of bulk GNRs. [Preview Abstract] 

C1.00013: Ideal Strength of graphene under general states of tensile strain MoonHyun Cha, Jeongwoon Hwang, Jisoon Ihm, KyungSuk Kim Phonon softening of graphene under general directional tensile strain is investigated based on ab initio density functional theory calculations. Under a wide range of tensile strain configurations, we demonstrate that phonon instabilities are responsible for the mechanical failure of graphene through the straininduced enhancement of phonon softening. It is shown that there are two types of phonon instabilities which induce symmetrybreaking structural distortions, and both of them lead to mechanical failure prior to the elastic failure commonly expected when the structural symmetry is retained. [Preview Abstract] 

C1.00014: Towards the assembly of structurally precise graphene nanoribbons for electronic applications Jia Gao, Fernando J. UribeRomo, Hasan Arslan, Colin Crick, Jonathan D. Saathoff, Paulette Clancy, William R. Dichtel, YuehLin Loo Graphene's lack of band gap has been a bottleneck that limits its use in transistors. One promising approach to open up a gap in its band structure is to narrow the width of graphene, i.e., make ``nanoribbons.'' Bottomup synthesis is a most promising method to produce structurally precise nanoribbons. But the assembly and patterning of these nanoribbons remains a challenge. In this study, we demonstrate a method for the assembly of structurally precise graphene nanoribbons. We observe preferential adsorption of nanoribbons on gold surfaces as opposed to silicon dioxide surfaces with aerosolassisted chemical vapor deposition. Importantly, we can tune the coverage of graphene nanoribbons through appropriate surface treatments. Graphene nanoribbon adsorption on a gold surface that had been modified with pentafluorobenzenethiol, for example, is higher than that on ozonecleaned gold, as evidenced by higher D and G band intensities in its Raman spectra. The ability to tune the surface coverage through surface treatment provides a unique opportunity to assemble and pattern graphene nanoribbons for electronic applications. [Preview Abstract] 

C1.00015: Simultaneous Adsorption of Water and Carbon Dioxide on GrapheneTitaniumSilicon Carbide System Gregorio RuizChavarria The adsorption of water and carbon dioxide has been studied separately in several works in recent times. These processes are important for the transcendence that would imply perform them in a simple and stable way. Controlling these processes we could fix carbon from the atmosphere and possibly obtain hydrocarbons. In a previous work [1], with colleagues, we performed a numerical calculation of the adsorption of water on a sheet of graphene. In this work I present a theoretical numerical calculation of the simultaneous adsorption of water and carbon dioxide on a titaniumgraphene system that relies on silicon carbide as substrate support. In this calculation we consider the interaction of water and carbon dioxide with the graphenetitanium system and the substrate, but also the interaction between water and carbon dioxide. In development of this calculation I used density functional theory, atomic pseudopotentials and molecular dynamics. I compare the results obtained with the reports of previuos works. \\[4pt] [1] Carbon, 47, 2 (2009), pp531533 [Preview Abstract] 

C1.00016: Electronic properties of rhenium and niobium doped tungsten disulfide monolayers Eduardo CruzSilva, Amber McCreary, Zhong Lin, Nestor PereaLopez, Ana Elias, Humberto Terrones, Mauricio Terrones Layered transition metal dichalcogenides (TMDs), have attracted great attention due to their electronic and optical properties. In particular, MoSand WSshow an indirect to direct electronic band gap transition when reduced to a monolayer, and display photoluminescence as a consequence. While there are proposed applications for MoSand WSas electronic and optoelectronic devices, control of their electronic properties needs to be reached before these applications can be scaled. In this sense, chemical doping has been recently shown to allow the modification of the electronic properties of MoSmonolayers by substitution of either transition metals or the chalcogen. Here we present a study of the electronic, magnetic, and chemical properties of doped WSmonolayers by performing \textit{ab initio }calculations. Substitution of tungsten atoms with either niobium or rhenium results in the formation of new states in the vicinity of the Fermi energy that allow to tailor the electronic band gaps, which results in different electronic and optical properties. [Preview Abstract] 

C1.00017: Preparation of graphene nanomeshes and nanoribbons using block copolymer lithography Zhiwei Sun, Thomas Russell Graphene nanoribbons and nanomeshes can find diverse applications in next generation electronic devices and energy technology, e.g. preparation of fieldeffect transistors and solar cell devices. Here, a facile way was proposed to prepare graphene nanomeshes and nanoribbons with reactive ion etching (RIE) using microphase separated poly(styreneb2vinylpyridine) (S2VP) thin film as template. Cylinder forming S2VP thin film was spincasted on top of graphene sheets on silicon wafer, which was prepared via chemical vapor deposition (CVD) on copper film. Cylinders in S2VP thin film would be aligned parallel to graphene substrate when exposed to THF vapor, while perpendicular to substrate when exposed to chloroform vapor. S2VP covered graphene films were then surface reconstructed in ethanol to enhance the etching contrast, followed by oxygen plasma reactive ion etching (O$_{2}$RIE). Block copolymer nanopatterns were successfully transferred to graphene films at appropriate etching conditions, and graphene nanoribbons and nanomeshes were formed. In addition, size and density of nanocavities on graphene were finetuned by changing molecular weight and chemical composition of the S2VP template. [Preview Abstract] 

C1.00018: Understanding the electronic, optical, and transport properties of Graphene deposited on GaN with varying surface roughness Nicole Creange, Kevin Hunter, Jason Haraldsen, Costel Constantin We examine the transport properties of graphene deposited on gallium nitride (GaN). Using density functional theory with local density approximations, we calculate the electric and thermal conductivity properties graphene as with varying GaN distortions. We show that local distortions of graphene due to surface defects of GaN have a significant effect on the electronic and thermal properties of graphene. [Preview Abstract] 

C1.00019: Doping graphene with BSO clusters Fernando Maga\~na, Gerardo Jorge Vazquez, Julio Lopez Sillenite crystals (Bi$_{12}$MO$_{20}$, M $=$ Ge, Si and Ti) present a number of interesting properties, such as photorefractive, piezoelectric, electrooptical, photoinduced absorption, optical activity and photoconductivity. Employing them at the nanoscale in electronic and optoelectronic devices may result in new applications. For example the electronic properties of inherently twodimensional (2D) materials such as graphene may be change by doping it with Bi$_{12}$SiO$_{20}$ (BSO) clusters. BSO is the fastest photorefractive crystal to date. By means of a calculation of first principles using the DFT, the density the levels of energy of molecules of BSO was investigated. The evolution was observed from the levels when going adding more molecules from BSO to the system, obtaining a behavior of the levels that looks like the levels in the bulk. In this work also was studied the effect on electronic properties of graphene when BSO clusters was added to it. [Preview Abstract] 

C1.00020: Screening Effect of Hexagonal Boron Nitride on Half Fluorinated Graphene Cristian Cernov, Shayan Hemmatiyan, Jairo Sinova Based on first principle calculations, we present the screening effects of hexagonal boron nitride (hBN) on the creation of a preference site for fluorine adsorption limited to one graphene sublattice. Furthermore, spinpolarized calculations indicate the overall magnetization of the system is antiferromagnetic. We also propose a possible spintronics application of halffluorinated hBN heterostructures. [Preview Abstract] 

C1.00021: New Approaches for Understanding of Hydrogen Interaction with Graphene, Graphene Hydroxide, and Lithiated Graphene Sourav Adak, Luke Daemen, Monika Hartl, Alice Smith, Daniele Paradiso, Nicholas Strange, George Thomas, J.Z. Larese A combination of solid state NMR, neutron vibrational spectroscopy, and volumetric adsorption isotherms have been employed to characterize graphene, hydroxylated graphene, and lithium incorporated graphene and the interaction of molecular hydrogen with them. Recent synthetic activities have produced materials with unique properties and when coupled with our ssNMR measurements the results shed some new light on the surface chemical composition of these materials and the role they play in the hydrogen storage capacity. Graphene is found to have significantly higher hydrogen uptake than graphite and randomly oxidized graphite sheets (graphite oxide). Inelastic neutron scattering (INS) provides direct information concerning hydrogen dynamics. We have used INS to examine how the interaction of hydrogen changes when the graphene surface chemistry changes or when lithium is incorporated at the interface. [Preview Abstract] 

C1.00022: Computational Design of Optoelectronic and Spintronic Devices in Graphene Nanoribbon Heterojunctions Avinash Prakash, Elif Ertekin Graphene is well known to possess outstanding electronic and structural properties. The potential of twodimensional materials in creating nextgeneration optoelectronic computing systems has been exhibited both computationally and experimentally. In this contribution, we use firstprinciples total energy electronic structure methods to develop design principles for optoelectronic devices, such as resonant tunneling diodes and double heterostructure lasers, in nanostructured graphene. A density functional theory approach utilizing nonequilibrium Green's functions and the LandauerB\"{u}ttiker formalism for ballistic transport provides the spinpolarized transmission spectrum and IV characteristics of the devices. These calculations can quantify the effects of nanoribbon topology on the device characteristics. We report negative differential resistance and spin filtering effects that can be engineered in novel logic circuits based on resonant tunneling. Our results provide the impetus to fabricate optoelectronic and spintronic devices from monomer organic molecules via bottomup chemical synthesis methods. We elucidate the applicability of graphene nanoribbons in optoelectronic molecular computing. [Preview Abstract] 

C1.00023: Fabrication of a graphene quantum dot device Jeong il Lee, Eunseong Kim Graphene, which exhibits a massless Diraclike spectrum for its electrons [1], has shown impressive properties for nanoelectronics applications including a high mobility and a width dependent bandgap [2]. We will report the preliminary report on the transport property of the suspended graphene nanoribbon(GNR) quantum dot device down to dilution refrigerator temperature. This GNR QD device was fabricated to realize an ideal probe to investigate Kondo physicsa characteristic phenomenon in the physics of strongly correlated electrons. \\[4pt] [1] K. S. Novoselov, \textit{et al.} Nature 438, 197200 (2005)\\[0pt] [2] YoungWoo Son, \textit{et al.} Nature 444, 347349 (2006) [Preview Abstract] 

C1.00024: Current flow and symmetry breaking in biased bilayer graphene Carlos Paez, Dario Bahamon, Ana Pereira A remarkable interest about bilayer graphene (BLG) is the possibility of opening a band gap and controlling its size when an electric field is applied between the layers. Many electronic devices based on these systems have been proposed, which involve usually the ability to control the layer degree of freedom, i.e., to explore the charge density asymmetry between layers induced by the bias. We investigate the transport properties along a biased BLG nanoribbon with zigzag edges, focusing on the current flow. We use a recursive Green's function method, and compare the charge density distribution in each layer with the current flow. The electric field breaks not only the layer symmetry but also the sublattice symmetry. Our results show that the current does not necessarily flow in the regions of the system with higher charge density. We show that current can flow mainly through one layer while the charge density is localized mainly over one of the edges of the other layer. We show results as a function of energy around Fermi energy and electric field, elucidating the main role of sublattice on the current flow. [Preview Abstract] 

C1.00025: Intact transfer of GaNbased devices via an hBN release layer: insights from firstprinciples study Gaoxue Wang, Mingsu Si, Haiying He, Ravindra Pandey As a promising material for the nextgeneration optoelectronic devices, most of high quality GaN films can only be grown on sapphire substrates at present. There is an urgent need of finding ways to transfer GaN to flexible substrates owing to the poor thermal conductivity of sapphire substrates, which has largely impeded the proper functioning and the largescale fabrication of GaNbased devices. Recently, mechanical transfer of GaNbased devices using hBN (Nature 484, 223 (2012)) as the release layer was proposed. In this study, we investigate the transfer mechanism by mapping out the interlayer sliding energy landscape at each interface of the heterostructures composed of GaN/BN/substrate together with the multilayered BN based on firstprinciples calculations. A nearly free sliding path is predicted for the BN bilayer, while much higher energy barriers are predicted for heterointerfaces. Thus, the mechanism, which is well described by the registry index model, shows that an easier slip can occur through the layered BN while the rest of the heterostructure remains intact. [Preview Abstract] 

C1.00026: Performance of Silicon Carbonitride Functionalized MoS$_{2}$ Nanosheets as Lithiumion Battery Anode Lamuel David, Romil Bhandavat, Uriel Barrera, Gurpreet Singh Liquidphase exfoliated MoS$_{2}$ was functionalized with polysilazane polymer to yield ceramic SiCNMoS$_{2}$ layered composite upon pyrolysis. Ceramization of polymer to ceramic phase on surfaces on MoS$_{2}$ was confirmed by electron microscopy and spectroscopic techniques. Electrochemical behavior of MoS$_{2}$ and SiCNMoS$_{2}$ on both traditional and paperbased electrode architecture was investigated in a Lithium ion battery halfcell configuration. All electrodes showed the classical 3phase behavior characteristic of a conversion reaction. SiCNMoS$_{2}$ composite paper showed more stable cycling and higher reversible capacity retention than MoS$_{2}$. The contribution of conversion reaction in MoS$_{2}$ or electrolyte decomposition in overall capacity was found to reduce in SiCNMoS$_{2}$ specimen, which is understood as one of the reason for decreased first cycle loss and increased capacity retention for SiCNMoS$_{2}$ composite. In addition, the freestanding composite paper exhibited excellent Crate performance, regaining approx. 97{\%} of its initial charge capacity when the current density was reduced to 100 mA.g$^{1}$ (508 mAh.g$^{1})$ from 2400 mA.g$^{1}$ (170 mAh.g$^{1})$. [Preview Abstract] 

C1.00027: Adsorption of ethane in carbon nanostructures Justin Petucci, M. Mercedes Calbi We explore the adsorption behavior of ethane on closeended carbon nanotubes and in asproduced carbon nanohorn aggregates. Adsorption isotherms and isosteric heats of adsorption are obtained by performing Grand Canonical Monte Carlo simulations. Results found for ethane adsorption on the external surface of nanotube bundles are compared with available experimental data and used to build a simple model of adsorption in the more complicated nanohorn structure. Analysis of the equilibrium configurations at increasing pressures provides information about the localization and orientation of the molecules in the different phases that correspond to the steps observed in the experimental and simulated isotherms. [Preview Abstract] 

C1.00028: Calculation of the Raman intensity in graphene and carbon nanotubes Marcus Moutinho, Pedro Venezuela Raman spectroscopy is one of the most important experimental techniques for characterization of carbon materials because it can give a lot of information about electronic and phonon structure in a non destructive way. We use a thirdorder quantum field model to obtain the theoretical Raman intensity for graphene and carbon nanotubes (CNT). The most important Raman peaks in graphitic materials comes from to the iLo and iTo phonon branches near to \textbf{$\Gamma$} and \textbf{K} points and, in this work, we focus our attention on some of these peaks, like the G, D and 2D bands, as a function of laser energy. The electronic and phonon dispersion used in our calculations reproduces the graphene \textit{ab initio} results with GW corrections and the zone folding method is used to obtain the CNT ones. Our results show that the experimental G band Raman excitation profile for CNT can be reproduced if we use the proper electronic and phonon dispersions. We also show that the phonon dispersion may influence the shape of the graphene D band and the dispersive behavior of the 2D band for graphene and CNT. [Preview Abstract] 

C1.00029: Kinetic Monte Carlo study of gas transport through a nanopore Joshua Vann, M. Mercedes Calbi We investigate the gas transport through a narrow pore by implementing a Kinetic Monte Carlo simulation on a single line of sites. Adsorption processes are restricted to the end sites that are in contact with gas reservoirs at different pressures. Particles gain access to the interior of the pore by hoping between the lattice sites. We follow the total uptake change with time as the system evolves to equilibrium, and we also examine the distribution of the particles along the pore at different times in the evolution. We analyze the overall dynamic behavior of the adsorbed phase in term of the occurrence of the elementary processes that drive the system to equilibrium. [Preview Abstract] 

C1.00030: Gas Adsorption Kinetics in Pores: A Computer Simulation Study Ramnath Selagamsetty, M. Mercedes Calbi We present results for the kinetics of adsorption of a gas inside a cylindrical pore. The study is based on a Kinetic Monte Carlo simulation performed on a lattice that includes a central line of sites encircled by a cylindrical shell of sites. We monitor the time evolution of the overall coverage as well as its distribution along the pore. We also keep track of the transfer of particles between the two groups of sites and analyze its consequences on the equilibration time of the system. We compare the resulting dynamics with the one observed for narrower pores where a single line of sites is considered. [Preview Abstract] 

C1.00031: Simulations of CO$_{2}$ adsorbed on a bundle of carbon nanotubes Mamadou Mbaye, Silvina Gatica, Justin Petrucci, Maria Calbi Using the method of grand canonical Monte Carlo (GCMC), we simulated the adsorption of CO$_{2}$ in a bundle of closed carbon nanotubes, for temperatures between 74K and 240K. From the outcome of the simulations, we computed the isosteric heat of adsorption, qst. The results are summarized as follows: 1) at low temperature the adsorption isotherms display two steps, which correspond to adsorption in the groove and monolayer completion respectively; 2) at a higher temperature, these steps are smoothed away; 3) at low coverage (up to one monolayer), the qst has the same behavior as for other gases (Ar, Kr) while at higher coverage, it differs from experimental findings. In our simulation the nanotubes were considered smooth, rigid hollow cylinders made of carbon with the density of graphene. The interaction CO$_{2}$NT was computed as the integration of a LennardJones potential plus the CO$_{2}$C quadrupolequadrupole energy. [Preview Abstract] 

C1.00032: Towards a more accurate van der Waals density functional Ikutaro Hamada The van der Waals density functional (vdWDF) of Dion {\it et al}. [1] has attracted considerable attention, because the functional is able to describe intra and intermolecular bondings with different natures, e.g., covalent and van der Waals bondings in a seamless fashion within the framework of density functional theory. However, the accuracy of the functional is yet to be improved for the applications to various systems. Here I propose an exchange functional for the second version of vdWDF [2], which improves the accuracy of vdWDF. The keys in the improved exchange are the matching to the gradient expansion approximation in the slowly varying limit and the large density gradient behavior set in Becke's exchange (B86b)[3]. Systematic study on gas phase molecules, solids, and molecular adsorption demonstrates the applicability of the proposed functional to a wide variety of materials. [1] M.~Dion {\it et al}., Phys. Rev Lett. {\bf 92}, 246401 (2004). [2] K.~Lee {\it et al}., Phys. Rev. B {\bf 82}, 081101 (R) (2010). [3] A.~D.~Becke, J. Chem. Phys. {\bf 85}, 7184 (1986). [Preview Abstract] 

C1.00033: Computational Analysis of Energy Pooling to Harvest LowEnergy Solar Energy in Organic Photovoltaic Devices Michael LaCount, Sean Shaheen, Garry Rumbles, Jao van de Lagemaat, Nan Hu, Dave Ostrowski, Mark Lusk Current photovoltaic energy conversions do not typically utilize low energy sunlight absorption, leaving large sections of the solar spectrum untapped. It is possible, though, to absorb such radiation, generating lowenergy excitons, and then pool them to create higher energy excitons, which can result in an increase in efficiency. Calculation of the rates at which such upconversion processes occur requires an accounting of all possible molecular quantum electrodynamics (QED) pathways. There are two paths associated with the upconversion. The cooperative mechanism involves a threebody interaction in which low energy excitons are transferred sequentially onto an acceptor molecule. The accretive pathway, requires that an exciton transfer its energy to a second exciton that subsequently transfers its energy to the acceptor molecule. We have computationally modeled both types of molecular QED obtaining rates using a combination of DFT and manybody Green function theory. The simulation platform is exercised by considering upconversion events associated with material composed of a high energy absorbing core of hexabenzocoronene (HBC) and low energy absorbing arms of oligothiophene. In addition, we make estimates for all competing processes in order to judge the relative efficiencies of these two processes. [Preview Abstract] 

C1.00034: Crystal structure prediction of Fe$_{3}$Se$_{4}$ using the evolutionary algorithm coupled with first principles DFT simulations Nabil AlAqtash, Renat Sabirianov The evolutionary algorithm coupled with the firstprinciples Density Functional Theory (DFT) method is used to identify the global energy minimum structure of Fe$_{3}$Se$_{4}$. The structure is processed by freeenergy based evolutionary crystal structure optimization algorithms, as implemented USPEX and XtalOpt codes, which predict structure of the system solely based on the chemical formula without prior experimental information. This is very challenging task for verifying the validity of this approach on Fe$_{3}$Se$_{4}$ structure. Fe$_{3}$Se$_{4}$ has highly anisotropic structure, and its structure demonstrates ordering of vacancies that makes the system ``open'', i.e. breaking traditional coordination rules. By using USPEX and XtalOpt we identify the global minimum of Fe$_{3}$Se$_{4}$ structure. The randomly generated initial population had 20 structures. The enthalpy (tolerance of 0.002 eV), and space group were used for niching. The enthalpy of the lowest energy structure, out of 700 generated structures that were generated, is (81.126 eV). Bulk Fe$_{3}$Se$_{4}$ has a monoclinic structure with a space group of \textit{I2/m} and $a =$ 6.208{\AA}, $b =$ 3.541{\AA}, and $c =$ 11.281{\AA}. The crystal structure and the lattice parameters of Fe$_{3}$Se$_{4}$ optimized from our calculations are similar to the experimental existing structure parameters. Fe$_{3}$Se$_{4}$ exhibits large magnetocrystalline anisotropy of 6x10$^{6}$ erg/cm$^{3}$ and coercivity up to 40kOe due to its unusual properties. [Preview Abstract] 

C1.00035: Generation of amorphous porous PdH: an \textit{ab initio} approach Isaias Rodriguez, Renela Valladares, Ariel A. Valladares, Alexander Valladares The hydrogen bubble template (HBT) method has been employed to generate amorphous porous structures in platinum, nickel, copper and gold. We used our \textit{ab initio} approach to generate amorphous porous $Pd_{50}H_{50}$; $Pd_{45}H_{55}$; $Pd_{40}H_{60}$, using an approach similar to the HBT method which keeps the interatomic distances the same as in the pure crystalline Pd, swapping palladium by hydrogen in a substitutional way, thus reducing the density and making the initial supercell metastable. We applied this HBTlike method to an initial 108atom crystalline facecentered cubic palladium supercell, with an initial density of $12.02 g/cm^3$. After the substitution we got three supercells: a crystalline supercell: Pd54H54, with a density of $6.056 \frac{g}{cm^3}$; a supercell: Pd49H59, with a density of $5.506 \frac{g}{cm^3}$; and a supercell: Pd43H65, with a density of $4.846 \frac{g}{cm^3}$. After the hydrogen insertion an MD process at $1000 K$ was applied, and the resulting structures finally relaxed. Pores appeared along welldefined spatial directions. We characterized the structures by means of the pair distribution function (PDF) and the bondangle distribution. Our results will be discussed in the light of possible structures of amorphous porous palladium hydride. [Preview Abstract] 

C1.00036: Size dependence in the stabilities and electronic properties of graphyne and its BN analogue V. Ongun Ozcelik, Salim Ciraci We predict the stabilities of $\alpha$graphynes and their boron nitride analogues($\alpha$BNyne), which are considered as competitors of graphene and twodimensional hexagonal BN [1]. Based on firstprinciples plane wave method, we investigated the stability and structural transformations of these materials at different sizes using phonon dispersion calculations and abinitio finite temperature, molecular dynamics simulations. Depending on the number of additional atoms in the edges between the corner atoms of the hexagons, $n$, both $\alpha$graphyne($n$) and $\alpha$BNyne($n$) are stable for even $n$, but unstable for odd $n$. $\alpha$graphyne($3$) undergoes a structural transformation, where the symmetry of hexagons is broken. We present the structure optimized cohesive energies, electronic, magnetic and mechanical properties of stable structures. Our calculations reveal the existence of Dirac cones in the electronic structures of $\alpha$graphynes of all sizes, where the Fermi velocities decrease with increasing $n$. The electronic and magnetic properties of these structures are modified by hydrogenation. \\[4pt] [1] V. Ongun Ozcelik and S. Ciraci, J. Phys. Chem. C, 2013, 117 (5), pp 21752182. [Preview Abstract] 

C1.00037: Enhancement of mechanical properties in multiscale hierarchical materials: when do we need them? Catalin Picu, Zhi Li, Monica Soare, Stefan Sorohan, Dan Constantinescu In this work we study numerically the macroscopic behavior of composites with hierarchical stochastic microstructures in order to determine under what conditions spatial correlations of microstructural features become important. Spatial correlations are used to define internal length scales or to eliminate them altogether (fractal structures). The behavior is compared with that of uncorrelated random microstructures. We show that as the range of spatial correlations increases, gains are observed in most macroscopic properties. Significant improvements are observed in the damping behavior. These results are important for the mesoscale design of nanocomposites and other multiscale engineered materials and structures. [Preview Abstract] 

C1.00038: Biphenylene Based SiGe Nanoribbons:An abinitio Study Prabath Wanaguru, Asok K. Ray A study of four types of biphenylene based SiGe nanoribbons had been performed using the cluster approximation. Full geometry and spin optimizations were performed without any symmetry constraints using the hybrid functional B3LYP, an all electron 6311G**//321G* basis set and the GAUSSIAN 09 suite of software. First phase of the calculations were carried out by keeping constant width (14 {\AA}) and varying length (12120 {\AA}) for the nanoribbons. It is found that armchair type nanoribbons have higher saturation HOMOLUMO gap (1.0 eV ) compared to zigzag like (0.2 eV) nanoribbons. Cohesive energy of the nanoribbons had increased with the length and saturated around 2.8 eV, for both armchair and zigzag like types. In the second phase, we have doubled the width of nanoribbons and found that the HOMOLUMO gap had decreased almost in half. Moving from smaller width to a larger width, ribbons were showing more of a sheet like character. We will present, in detail, cohesive energies, HOMOLUMO gaps, density of states, and the bonding nature of Si and Ge atoms within the nanoribbons. [Preview Abstract] 

C1.00039: Data Mining with Molecular Design Rules Identifies New Class of Dyes for DyeSensitized Solar Cells Jacqueline Cole A major deficit in suitable dyes is stiffling progress in the dyesensitized solar cell (DSC) industry. Materials discovery strategies have afforded numerous new dyes; yet, corresponding solutionbased DSC device performance has little improved upon 11{\%} efficiency, achieved using the N719 dye over two decades ago. Research on these dyes has nevertheless revealed relationships between the molecular structure of dyes and their associated DSC efficiency. Here, we have codified such structureproperty relationships in the form of molecular dye design rules, which have been judiciously sequenced in an algorithm to enable largescale data mining of dye structures with optimal DSC performance. For the first time, we have a DSCspecific dyediscovery strategy that predicts new classes of dyes from surveying a representative set of chemical space. A lead material from these predictions is experimentally validated herein, showing DSC efficiency that is comparable to many wellknown organic dyes. This demonstrates the power of this approach. [Preview Abstract] 

C1.00040: Experimental Realization of Theoretically Predicted New Stable Inorganic ABX Materials Andriy Zakutayev, Xiuwen Zhang, Liping Yu, Stephan Lany, David Ginley, Alex Zunger Inorganic materials with ABX stoichiometry are an important class of compounds that is under research for numerous applications. Systematic search across databases and literature indicates that many ABX materials are unreported [1], for example 29 out of 45 materials in the VIXIV 18electron family. Theoretical calculations reveal that 8 of these VIXIV materials are thermodynamically stable, including 4 new materials with halfHeusler structure. Thin film combinatorial synthesis experiments using sputtering, xray fluorescence and xray diffraction confirm that one of these materials TaCoSn is stable in the predicted halfHesuler structure. [2] Despite being made of three metallic elements, TaCoSn is a semiconductor, but the band gap of this material is difficult to measure due to a high concentration of interstitial cobalt defects. [1] Adv. Func. Mat. 22, 1425 (2012) [2] J. Am. Chem. Soc. 135, 10048 (2013) [Preview Abstract] 

C1.00041: A comprehensive molecular dynamics study on the selfassembly and properties of SiC based cage structures Congyan Zhang, ZiHua Xin, Ming Yu, C.S. Jayanthi, S.Y. Wu A molecular dynamics study to investigate a plausible way of fabricating SiC based cage structures has been performed. In this work, the existence of the stable SiC based cage nanostructures SimCn with the size up to about 2.05nm in diameter and the compositions n/(n$+$m) from 0.4 to 0.6 has been demonstrated using an efficient semiempirical Hamiltonian method (SCEDLCAO) [PRB 74, 15540 (2006)]. The structural properties are analyzed in terms of the composition, the bonding nature, the surface environment, the local strain, and types of ring structures. It is found that the sp$^{\mathrm{2}}$ bonding nature between Si and C atoms and the environmental mediation are two key factors for the selfassembly of the stable SiC based cage structures. In particular, the transition from one stable cage structure to another of similar composition might occur due to the mending process in the selfassembly. [Preview Abstract] 

C1.00042: The Structural study of Spin Coated Thin Film Magnets Amber LaGuerre, P. Samarasekara, Rasika Dahanayake, Sunil Dehipawala Recently there has been a very high demand for small scale magnetic storage devices. The industry sector has consistently demanded sub micron or even nanometer scale magnets. Magnetic thin films often contain several layers of coating. For the purpose of the study, we prepared thin film magnets by spin coating a precursor containing iron and nickel into a glass substrate. The thickness of the films were controlled by the spin rate. Precursor films on the substrate were then annealed to either 200$^{\circ}$C to 350$^{\circ}$C for up to 2 hours in air. The micro structure of iron in the films was investigated using Xray Absorption Near Edge Structure (XANES) and Extended Xray Absorption Fine Structure (EXAFS). The main absorption edge peak position and preedge energy position was identical in all of the samples. This indicates that there was no change in the charge state of the iron regardless of the number of layers and annealing temperature. However the main absorption edge jump, which is proportional to the amount of iron, varied depending on the experimental conditions. [Preview Abstract] 

C1.00043: Generalized stacking fault energetics in FePt nanoparticles and effects of extended defects on magnetocrystalline anisotropy Ahmad Alsaad, Nabil AlAqtash, Renat Sabirianov \textit{ab inito} calculations are carried out to study the generalized stacking faults energetics of extended defects observed experimentally in FePt nanoparticles. We calculated $\gamma $surface energy of FePt with antiphase boundary by shifting two crystallites against each other. The $\gamma $energy is calculated using \textit{slab approach.} Each crystallite is stacked along the [001] direction and terminated by Pt layer at the antiphase boundary. We used eight layers of L1$_{0}$FePt, four of Fe layers and the other four are Pt layers. The aligned crystals position atoms of Pt directly on top of each other across the interface of two crystallites (point C). In this case, it appears that Fe layer is missing from the regular FePt lattice. A shift by (0.5, 0.5, 0.0) aligns crystallites perfectly in terms of site position of L1$_{0}$ lattice, but Fe and Pt interchange their site occupancy across the boundary (Point A). Another, high symmetry point of $\gamma $surface is located at the shift of (0.25, 0.25, 0) (point B). In this case, Pt atoms are coordinated by two Pt atoms across the interface and it corresponds to a bridge position between two global minima of $\gamma $surface. We calculated $\gamma $surface energy along the path connecting the above high symmetry points A$\to $B$\to $C$\to $A and estimate the defect energy to be about 0.5eV/atom. Magnetocrystalline anisotropy energy (MAE) of the defect at point A is found to be 54.11 Merg/cm$^{3}$ along caxis, while MAE decreases to 42.34 Merg/cm$^{3}$ at points C. Thus, extended defects may affect the magnetization reversal of FePt nanoparticles. [Preview Abstract] 

C1.00044: Influence of rare earth elements on photovoltaic properties of nanocrystalline silicon thin film solar cells Irina Bariakhtar, M. Naughton, M. Burns, Yu. Yakimenko, A. Ivashchuk, V. Koval, Yu. Yasievich, M. Dusheyko The silicon nanocomposites (ncSi) with rare earth elements (REE) are the new materials used in optoelectronics. The presence of REE is the cause of the photoluminescence in a silicon nanomaterial and is well studied[1]. However, the introduction of REE impurities into a silicon nanocomposite with the semiconductor matrix ($\alpha $Si) appears to be a promising new technology, since such materials can be used in photosensors and thinfilm solar cells. It is known that the RE metal impurities can significantly improve transport properties of the material. Such methods have been already used in some solar technologies [2]. Additionally, they can improve photosensitive properties of a material and the REEs with a double valence create the optical impurity centers of a different nature. Finally, some RE ions, e.g. Eu, can effectively absorb UV radiation due to the specific structure of their energy levels [3]. In this presentation, we discuss the influence of the REE on the photovoltaic properties of the nanocrystalline silicon solar cells, their optical characteristics and energy adsorption properties 1. M. Losurdo \textit{et al., }(2003)\textit{ Physica E} \textbf{16}, 414. 2. C. Benvenuti, (2013), \textit{Europhysics News} \textbf{44} (3), 16. 3. M.M. Mezdrogina \textit{et al}. (2002) \textit{Semiconductors }36 (11), 1337. [Preview Abstract] 

C1.00045: Investigation of xerogel sensor materials by soft xray laser ablation mass spectrometry Marina Pilipenko, Ilya Kuznetsov, Jorge Filevich, Mark Woolston, David Carlton, Weilun Chao, Erik Anderson, Jorge Rocca, Alexander Koshkin, Carmen Menoni Xerogels possess many properties that make them prospective candidate for new generation sensor material. By modification of a wellestablished gel synthesis method, based on supercritical drying, it was possible to obtain a lowcost and highly porous compound. This material has micro volume printing capability, i.e. can be spincoated to form a thin film. With stable sensing molecules introduced into the pores of its matrix, xerogels provide a fluorescent response to vapors of target compounds, making them identifiable at low concentrations in the air. There are many factors that influence the stability of the xerogel and the reliability of the response signal appearance  from choosing the right synthesis method to selecting a proper sensor molecule. We have investigated the chemical composition of xerogels by soft xray laser ablation mass spectrometry. Various morphologies of the printed films as a function of gel formation stage were demonstrated. Results will be presented on the influence of Nile Red dye sensor molecules on the matrix structure with the volumetric distribution shown. [Preview Abstract] 

C1.00046: Self Healing of Vacancy Defects in Single Layer Graphene and Silicene V. Ongun Ozcelik, Hakan Gurel, Salim Ciraci Self healing mechanisms of vacancy defects in graphene and silicene are studied using first principles calculations[1]. We investigated host adatom adsorption, diffusion, vacancy formation and revealed atomistic mechanisms in the healing of single, double and triple vacancies of single layer graphene and silicene. Silicon adatom, which is adsorbed to silicene at the top site forms a dumbbell like structure by pushing one Si atom underneath. The asymmetric reconstruction of the single vacancy in graphene is induced by the magnetization through the rebonding of two dangling bonds and acquiring a significant magnetic moment through remaining unsaturated dangling bond. In silicene, three twofold coordinated atoms surrounding the single vacancy become fourfold coordinated and nonmagnetic through rebonding. The energy gained through new bond formation becomes the driving force for the reconstruction. Under the external supply of host atoms, while the vacancy defects of graphene heal perfectly, StoneWales defect can form in the course of healing of silicene vacancy. The electronic and magnetic properties of suspended, single layer graphene and silicene are modified by reconstructed vacancy defects. [1] V. Ongun Ozcelik, H. Gurel, and S. Ciraci, Phys. Rev. B 88, 045440 (2013)]. [Preview Abstract] 

C1.00047: Study of Pair MirrorResonance in Fibonacci Arrays with Sagittal Waves Lamberto CastroArce, Julio Cesar CamposGarc\'Ia, Carlos FigueoaNavarro, Mart\'In Eduardo MolinarTabares The states of polarization of sagittal waves in quasiperiodic structures of Fibonacci type are studied. Complementary to the periodic case where the state of polarization is obtained through the average of the longitudinal and transversal energies in an unitary cell, and for a super cell (periodic case with defect), we will evaluate here the polarization of elastic waves in plates with arrays of different levels or Fibonacci orders. Also the mirror effect, increasing the Fibonacci level we have found an additional structure in the spectrum of reflected and transmitted energy. We observe not just the appearance of the resonance but also the emergence of a new peak of reflection of the longitudinal wave. Through the analysis of the multilayer structure Fibonacci level 6, in practice we are creating a superstructure in blocks. [Preview Abstract] 

C1.00048: Work functions and transport properties of finite metallic hexaboride nanorods Lu Wang, Guangfu Luo, Renat F. Sabirianov, WaiNing Mei, Daniel Valencia, Carlos H. Sierra Llavina, JunQiang Lu, Chin Li Cheung We performed density functional theory calculations of finite metallic hexaboride LaB$_{\mathrm{6}}$ nanorods, which are regarded as good thermoelectric materials for their low work functions. Our purpose is to facilitate the research and manufacture of metal hexaboride probes, thus we study extensively the work functions and electron transport properties of these finite nanorods. The work functions were deducted from the calculated electrostatic potential and the Fermi energy. We found that these finite LaB$_{\mathrm{6}}$ nanorods have low work functions similar to their infinite counterpart. To further investigate the electron transport properties, we adopted the combined LandauerButtiker formalism and nonequilibrium Green's function technique to compute the transmission coefficients near the Fermi level and found that the finite LaB$_{\mathrm{6}}$ nanorods can be converted from metallic to semiconducting by applying a gate voltage larger than 10 V. [Preview Abstract] 

C1.00049: ExcitonPlasmon Coupling in MetalNanoparticleDecorated ZnO/MgO CoreShell Nanowires Daniel Mayo, Claire Marvinney, Ephraim Bililign, James McBride, Richard Mu, Richard Haglund Zinc oxide has emerged as one of the most promising optoelectronic materials due to its direct bandgap of 3.37 eV and large exciton binding energy of 60 meV. Room temperature photoluminescence (PL) spectra for ZnO exhibit a sharply defined exciton recombination peak centered at 3.3 eV and a broad visible defect peak centered around 2.3. A wide range of optoelectronic devices, including LEDs, lasers and sensors, have been developed by tuning ZnO emission through different growth, annealing, and doping conditions. However, one of the most effective methods for PL enhancement is through coupling of localized surface plasmons of metal nanoparticles to the ZnO luminescent centers. ZnO nanowires are decorated variously with Ag, Al, and Au nanoparticles, with an insulating MgO interlayer used to differentiate plasmonmediated emission due to hotelectron transfer from that due to local field effects. In addition, at specific MgO thicknesses, FabryPerot resonators within the coreshell nanowires result in dramatic enhancement of the bandedge PL while the visible emission remains unaffected. A large variation in the bandedge emission occurs for the various nanoparticle species, with Al exhibiting the strongest plasmonic coupling and therefore the highest PL enhancement. [Preview Abstract] 

C1.00050: Highly branched RuO2 Nanorods on Electrospun TiO2 Nanofibers toward Electrochemical Catalysts Yukyung Cho, SuJin Kim, NamSuk Lee, Myung Hwa Kim, Youngmi Lee We report a facile growth route to synthesize hierarchically grown single crystalline metallic RuO$_{2}$ nanorods on electrospun TiO$_{2}$ nanofibers via a combination of a simple vapour phase transport process with an electrospinning process. This synthetic strategy could be very useful to design a variety of highly branched network architectures of the functional heteronanostructures for electrochemical applications. Particularly, Ruthenium oxide (RuO$_{2})$ 1dimensional nanostructures can be used as the effective catalysts or electrochemical electrode materials. Thus, we first synthesize TiO$_{2}$ nanofibers from mixture of titanium isopropoxide precursor and polymer and then ruthenium hydroxide precursor on TiO$_{2}$ nanofibers are transformed into RuO2 nanorods by thermal treatment at 250$^{o}$C in air. The crystalline structures of products are confirmed using scanning electron microscopy (FESEM), Xray diffraction (XRD) spectrum, Raman spectroscopy, and high resolution electron microscopy (HRTEM). The fundamental electrochemical performances are examined using cyclic voltammetry (CV). [Preview Abstract] 

C1.00051: Sonoluminescence of carbon nanotubes Oleksiy Roslyak, Piryatinski Andrei We report strong reduction in photoluminescence spectra of single wall semiconducting carbon nanotubes in presence of surface acoustical wave (SAW) in a piezoelectric substrate. In conventional Stark effect the excitonic oscillator strength is effectively transferred to the electronhole manifold by reducing the exciton binding energy. Or formalism attributes the reduction to an effective damping of the electron velocity matrix elements at the Van Hove singularities of the SAW induced superlattice. The effect manifests itself in absorption spectra by reducing the peaks amplitudes linearly with SAW amplitude in the GHz acoustical regime. Crossover to the Starklike quadratic dependence on SAW amplitude occurs in low THz regime. We also report better quenching of higher order exciton absorption peaks as compared to the lowest optically active exciton. [Preview Abstract] 

C1.00052: Bound states of singlelayer and bilayer graphenes with onedimensional potential Akihiro Okamoto, Takehito Yokoyama, Shuichi Murakami Both the graphene and a surface of a topological insulator have Dirac cones. For a Dirac cone on a surface of a topological insulator, a onedimensional potential well leads to bound states with linear dispersions [1]. A similar behavior is expected for graphene. We study behaviors of bound states in singlelayer and bilayer graphenes with a onedimensional potential well. In bilayer graphene within the continuum model, two types of bound states coexist. One exists only within a finite range of the wavenumber, while the other exists for any wavenumber. We also compare the results for the continuum model with that of the lattice model in the singlelayer and bilayer graphenes. We present how these bound states change as the potential energy is changed.\\ $[1]$ T. Yokoyama, A.V.Balatsky, and N. Nagaosa, Phys. Rev. Lett. 104, 246806 (2010). [Preview Abstract] 

C1.00053: Heavy adatoms and Anderson localization in graphene Jose H. Garcia Aguilar, Bruno Uchoa, Lucian Covaci, Tatiana G. Rappoport We analyze electronic localization in a graphene layer doped with adatoms sitting in the center of the honeycomb hexagon, as happens with the heaviest adatoms. In this configuration, the hybridization between the adatom orbitals and its neighboring carbon atoms mediate hopping processes that connect all six vertices of the honeycomb hexagon around the impurity. The amplitudes of the hopping depend on the symmetry of the orbital that hybridizes with graphene, leading to an orbitaldependent ``plaquette disorder''. To capture the physics of localization, we propose an effective grapheneonly Hamiltonian that preserves the associated orbital symmetries and conduct a scaling analysis of the local density of states (LDOS) for large system sizes. We show that adatoms that form a zeroenergy resonant state lead to Anderson localization in the vicinity of the Dirac point. Among those, we show that there is a symmetry class of adatoms for which Anderson localization is suppressed, leading to an exotic quantum critical metallic state with large charge puddles, that localizes only at the Dirac point. [Preview Abstract] 

C1.00054: Electronic structures transition for sliding bilayer graphene: A Firstprinciples study BiRu Wu The weak interlayer interactions of bilayer graphene strongly affect the electronic structure in the low energy region. The stacking manner of graphene dominates the interlayer interaction and determines the band structure in the low energy region. However, the total energy difference between the most unstable AA stacked bilayer graphene and the most stable AB one is less than 5 meV per carbon atom. It means the sliding between the two layers of graphene is possible. We investigate the electronic structure transition of the sliding bilayer graphene via density functional theory. The graphene layer slides along the armchair and zigzag directions over whole unit cell are studied. The energy surface of the upper layer graphene sliding over whole unit cell reveals that the AA stacking manner has the highest energy and the AB stacked one has the lowest energy as expected, and one saddle point is observed for the AD stacked manner. For the electronic structure transition, the merging of Dirac points and gap opening are found during the sliding process. [Preview Abstract] 

C1.00055: Thermoelectric power in a bilayer graphene device Chien YungYu, Yuan Hongtao, Wang ChangRan, Lin ChunHsuan, Lee WeiLi There have been great interests on band gap engineering in a bilayer graphene (BLG) device, where inversion symmetry breaking by a perpendicular electric field can give rise to a sizable band gap. In our previous works, we have demonstrated a large enhancement in the thermoelectric power (TEP) associated with the band gap opening in a dualgated BLG device. It is, therefore, an interesting question to ask whether even larger TEP can be achieved with a larger perpendicular electric field applied. We explored such possibility by utilizing the ionic liquid gating technique in BLG devices. By controlling the side gate voltage of ionic liquid and the bottom gate voltage via SiO$_{2}$/Si substrate, large increase of the sheet resistance at charge neutral point was observed suggesting the opening of a band gap. At T $=$ 120 K, TEP increases by more than 44{\%} with a side gate voltage of $\sim$ 1V. The influence of charge puddles to TEP using ionic liquid gating will be discussed. [Preview Abstract] 

C1.00056: Secondorder nonlinear optical susceptibility for gapped graphene Yonatan Abranyos, Godfrey Gumbs, Upali Aparajita, Oleksiy Roslyak The secondorder nonlinear optical susceptibility $\chi^{(2)}$ for second harmonic generation is calculated for gapped graphene. The linear response plasmon excitation as well as the secondorder nonlinear plasmon excitations are investigated. We report a red shift which is an order of magnitude enhancement of that resonance with growing gap, or alternatively, reduced electrochemical potential. [Preview Abstract] 

C1.00057: Light Injection into Thin Nonabsorbing Dielectric Slabs with Graphene as Coupler Felipe RamosMendieta, Alejandro Hern\'andezL\'opez, PalominoOvando Martha Evanescent TE electromagnetic fields produced by the Attenuated Total Reflection (ATR) technique fail to excite guided modes of a thin dielectric slab. However, we found that wave guidance arises when such slab is coated on graphene. The complex optical conductivity of (the zero thickness) graphene modifies the effective dielectric constant of the dielectric slab giving place to the physical mechanism for the mode coupling. We demonstrate that in slabs as thin as 1 $\mu$m of dielectric constant of order of 2.25, the modes are excited by fields in the 30  70 THz regime. This is, up and down of the threshold frequency of the interband absorption, $f_{th}$ $\sim$ 48 THz, which is a characteristic of the optical conductivity of high doped graphene. The effect is not related to the surface TE plasmons of graphene because the phenomenon exists beyond the plasmonic frequency regime (41  48 THz). A complete theoretical study including dispersion relations and field profiles of the excited modes is presented. [Preview Abstract] 

C1.00058: Landau Orbit Mixing in Modulated Bilayer Graphene Paula Fekete, Girija Dubey, Godfrey Gumbs, Andrii Iurov, Danhong Huang Recently, the Landau level (LL) spectrum of bilayer graphene has been the subject of much discussion since its formation depends on whether the stacking is AA or AB arising from positioning the atoms in the underlying sublattices. This difference in stacking may affect the transport and optical properties of the bilayer. So far, little attention has been given to the electron energy bands of bilayer graphene when a strong electrostatic modulation is applied in the presence of a uniform magnetic field perpendicular to the bilayer. Using a model Hamiltonian for AB stacking, we investigate the modiffication of the LLs by a twodimensional periodic array of scatterers and the effect of modulated LLs on transport and optical properties of the bilayer. [Preview Abstract] 

C1.00059: Zeroenergy traps and magnetic flux readout in graphene Charles A. Downing, Kumar S. Gupta, Mikhail E. Portnoi There is a widespread belief that electrostatic confinement of graphene charge carriers, which resemble massless Dirac fermions, is impossible as a result of the Klein paradox. We show that full confinement is indeed possible for zeroenergy states in pristine graphene with careful modulation of the strength of the trapping electrostatic potential. The addition of a magnetic flux tube to the system requires one to perform a oneparameter selfadjoint extension of the Dirac Hamiltonian to completely define the spectrum of the zeromodes, which can be carried out using the method of deficiency indices developed by von Neumann. We propose such a magnetic vector potential as an additional means to control these optimal quantum dots supporting zeroenergy states and bring about confinementdeconfinement on demand. The considered system can be utilised in novel graphenebased magnetic readout devices. C. A. Downing, D. A. Stone, and M. E. Portnoi, Phys. Rev. B 84, 155437 (2011). C. A. Downing, K. S. Gupta, and M. E. Portnoi (in preparation). [Preview Abstract] 

C1.00060: Dynamics of intermolecular Auger decay at a surfacechemisorbate interface Piotr Matyba, Adra Carr, Cong Chen, Margaret M. Murnane, Henry C. Kapteyn, David L. Miller, Mark W. Keller, Guowen Peng, Manos Mavrikakis, Steffen Eich We use ultrafast high harmonic xray pulses to follow the relaxation dynamics of the 2p corehole in Na chemisorbed on graphene/Ni(111).[1] A coreexcited Na atom cannot fill the 2p corehole through Auger decay since the 3s shell has only one electron. In Na dimers or metal however, Auger decay is possible via interatomic or LVV Auger decay since the 3s electrons are shared or form a valence band (VB). The lifetimes of the 2p corehole in dimers (15$+$/8 fs) and metal (51$+$/7 fs) are relatively long due to coupling and many body interactions.[2, 3] In a submonolayer of Na on graphene/Ni(111), the 3s electrons do not form a VB but populate the empty $\pi $* state of graphene. Our measurements show that the LVVlike decay is still possible in such a system. Moreover, the lifetime of the 2p corehole is exceptionally short (\textless 2 fs to 7 fs depending on the coverage) when compared to Na dimers or metal. We conclude that this fast decay is mediated by the graphene and its delocalized $\pi $ and $\pi \ast $ electrons, and due to the strong Nagraphene bonding, is akin to Auger rather than to intermolecular Coulomb decay. [1] A. V. Carr et al., in preparation (2013), [2] T. Rander et al., Physical Review A 75 (2007), [3] T. A. Callcott et al., Physical Review B 18, 6622 (1978). \newline [Preview Abstract] 

C1.00061: Next Generation Epigenetic Detection Technique: Identifying Methylated DNA using Graphene Nanopore Towfiq Ahmed, Jason T. Haraldsen, JianXin Zhu, A.V. Balatsky DNA methylation plays a pivotal role in the genetic evolution of both embryonic and adult cells.Unusual methylation on CPG islands are identified as the prime causes for silencing the tumor suppressant genes. Early detection of such methylation can diagnose the potentially harmful oncogenic evolution of cells, and provide a promising guideline for cancer prevention.We propose a detection technique and calculate the transport current through punctured graphene as the cytosine and methylated cytosine translocate through the nanopore. We also calculate the transport properties for uracil and cyanocytosine to compare. Our calculations of transmission, current and tunneling conductance show distinct signatures in their spectrum for each molecular type. Our theoretical study provides a next generation detection technique for identifying DNA methylation using graphene based nanopore device. [Preview Abstract] 

C1.00062: Chiral symmetry breaking and integer and fractional quantum Hall effects in monolayer graphene Bitan Roy, Malcolm Kennett Integer quantization of Hall conductivity near the Dirac points in graphene is unique in the sense that only electronelectron interactions can resolve the four fold valley and spin degeneracy, which in turn gives rise to Hall plateaus at filling $\nu=0, \pm 1$. In this work, we will argue that generation of chiral symmetry breaking orderings such as antiferromagnetic and chargedensitywave orders, provides an excellent variational description of the Hall states at $\nu=0,\pm 1$. For realistic strength of the subcritical shortranged Coulomb interactions, the solutions of the selfconsistent gap equations are in very good agreement with the recently observed scaling of the interaction induced gap at $\nu =0, \pm 1$ with magnetic field as measured with a variety of different techniques. Although Zeeman coupling changes the nature of the broken symmetry phases, it otherwise leads to better agreement with experimental results. A possible explanation of recently observed hierarchy of fractional Hall states within the framework of chiral symmetry breaking ordering inside the zeroth Landau level in graphene will also be highlighted. [Preview Abstract] 

C1.00063: STRONGLY CORRELATED SYSTEMS, INCLUDING QUANTUM FLUIDS AND SOLIDS 

C1.00064: Ferroelectricresistive switching effect in BiFeO$_{3}$ nanoislands Taekjib Choi, Ji Hoon Jeon, Yunseok Kim, Sergei V. Kalinin, Bae Ho Park Recent investigations into various ferroelectric materials have revealed remarkable polarization dependent electronic transport properties. These properties include a significant electroresistance changes in a switchable ferroelectric diode and ferroelectric tunnel junctions However, ferroelectric nanostructures such as nanoislands and nanowires have not yet been exploited for ferroelectricresistive memories In this presentation, we explore the local charge conductions and their coupling with ferroelectric polarization in highly ordered ferroelectric BiFeO$_{3}$ nanoislands array by using conductive atomic force microscopy and piezoresponse force microscopy. We observed a switchable diode effect in BiFeO$_{3}$ nanoislands grown on SrRuO$_{3}$/SrTiO$_{3}$ substrate The ratio of resistive on/off had a value of $\sim$ 753, reading with a voltage as low as $\sim$ 0.5 V These results suggest that ferroelectric nanostructures as a potential candidate for ferroelectricresistive memory elements can provide higher resistive on/off ratio, lower power consumption and large capacity. [Preview Abstract] 

C1.00065: Symmetry based approaches to discovering new improper ferroelectrics / multiferroics John Claridge, Matthew Dyer, Matthew Rosseinsky The area of improper ferroelectrics and potentially multiferroics has recently received significant attention do the prediction that a combination of a$^{}$a$^{}$c$^{+}$ tilting and layered ordering of the A site cations along [001]$_{\mathrm{perov}}$ in perovskite ABX$_{3}$ systems, leads to noncentrosymmetric structures which are predicted to have significant switchable polarisations. Here we elaborate a superspace description of cation ordering in tilted perovskites that allows the prediction of the symmetry of arbitrary cation ordered superlattices, along \textless 100\textgreater $_{\mathrm{perov}}$, \textless 110\textgreater $_{\mathrm{perov}}$ and \textless 111\textgreater $_{\mathrm{perov}}$ and ordering of both A and B cations, of the various tilted perovskites, which also rationalizes the observed domain structures. This approach is expaned to include magnetic symmetry and the potential for finding other suitable structural distortions in different systems will be discussed. [Preview Abstract] 

C1.00066: ABSTRACT WITHDRAWN 

C1.00067: Structural, transport, and magnetic properties of narrow bandwidth Nd$_{1x}$Ca$_{x}$CoO$_{3\delta}$ and comparisons to Pr$_{1x}$Ca$_{x}$CoO$_{3\delta}$ Daniel Phelan, Christopher Leighton, Yusuke Suzuki, Shun Wang, Ashfia Huq Pr$_{1x}$Ca$_x$CoO$_{3\delta}$ (PCCO), has drawn attention due to a 1storder insulatormetal transition (IMT) that appears on cooling at x=0.5, connected to a shift in electron occupancy between Pr and Co sites. Furthermore, the evolution of the magnetic/transport properties in lowbandwidth (LB) cobaltites is of interest due to anticipated enhancement of magnetoelectronic phase separation by suppressed bandwidth. We discuss the structural, magnetic, and transport properties of a second series, Nd$_{1x}$Ca$_x$CoO$_{3\delta}$ (NCCO, 0$\leq x\leq0.4$), which, devoid of the unique PrO bonding in PCCO, serves as a control for assessing the intrinsic physics of LB cobaltites. Using smallangle neutron scattering, neutron diffraction, and AC/DC magnetometry, a magnetic phase diagram is developed. Common to both systems is development of a metallic ferromagnetic (FM) state with low T$_c$ ($<$ $\sim$60 K for NCCO) upon hole substitution, while at higher temperatures ($\sim$270 K for NCCO), shortrange FM is stabilized, likely around O vacancies. Phase separation leads to exchangespring behavior around $T_c$. Unique to NCCO is ferrimagnetic ordering ($<$ $\sim$14 K) involving Nd. Absence of a 1storder IMT in NCCO affirms the influence of PrO bonding on the IMT in PCCO. [Preview Abstract] 

C1.00068: Effect of titanium substitution on the structural and magnetic properties of cobalt ferrite Cajetan Nlebedim, David Jiles Spinel crystal structure in ferrites presents various degrees of freedom in altering their magnetic and related properties to specific applications. Such degrees of freedom include choice of cation site to substitute into, choice of substitution for either Fe or Co or even both, and the ability to alter the site occupancy of the substituted cation. In this work, the effect of cosubstituting Ti$^{4+}$/Co$^{2+}$ into cobalt ferrite has been found to result in a nonlinear variation in lattice parameter. This is in agreement with a previous report on a similar material that the rate at which cations substitutes into the cation sites varies with Ti$^{4+}$ concentration. Ti$^{4+}$ substitution resulted in almost a linear decrease in saturation magnetization. The coercivity and differential susceptibility varies inversely. The trend in the variation of the magnetic properties is remarkably consistent with the cation distribution, previously reported on a similar material. The correlation between the lattice parameter and magnetic properties further indicates that the observations are due to the cation distributions in the material. [Preview Abstract] 

C1.00069: NiMoO3, a new half metal predicted by first principles Zhijian Wu, Jing Wang Halfmetallic (HM) materials are metallic for one spin direction while at the same time semiconducting for the other spin direction [1]. In our recent study, NiMoO3 is designed and studied by the first principles [2]. It is isostructural and isovalent to experimental synthesized NiCrO3. Compensated half metal is obtained when considering electron correlation alone. Inclusion both spin  orbit coupling and electron correlation induce a large orbital moment on Ni ( 0.23 $\mu$B) due to the Coulomb enhanced spin  orbit coupling. This makes NiMoO3 a half metallic ferrimagnet with nonintegral magnetic moment. \\[4pt] [1] de Groot, R. A.; Mueller, F. M.; van Engen, P. G.; Buschow, K. H. J. Phys. Rev. Lett., 1983, 50, 2024.\\[0pt] [2] Wang, J., Wu, Z. J. Appl. Phys. Lett, 2012, 101, 042414. [Preview Abstract] 

C1.00070: Effective of charge doping in the LaNiO$_3$/SrTiO$_3$ superlattices HeungSik Kim, Myung Joon Han In this study we investigate the charge doping effect on the crystal and electronic structure of LaNiO$_3$/SrTiO$_3$ superlattice with densityfunctional theory calculations. It is found that the doped charge favors Ni $d_{3z^2  r^2}$ orbital, and that the NiO$_6$ octahedron is elongated or compressed along the $z$direction in order to reduce the energy. Under the fixed inplane lattice constant, the octahedral distortion upon charge doping can be understood as a dopinginduced effective epitaxial strain. The rotation of the NiO$_6$ octahedra is affected by the charge doping and the resulting dopinginduced effective strain. Inclusion of the electron correlations enhances the orbitallattice coupling and the structural changes. Possible cupratelike Fermi surfaces induced by hole doping will also be discussed. Our work provides insights on the effect of charge doping on the nickelate superlattices, and suggests a dopingcontrolled structural evolution in these systems. [Preview Abstract] 

C1.00071: ABSTRACT WITHDRAWN 

C1.00072: ContactFree Electrical Measurements of VO2 Powder Benjamin Huber, Will Hardy, Heng Ji, Douglas Natelson Vanadium dioxide (VO$_{\mathrm{2}})$ is a strongly correlated transition metal oxide with a metalinsulator transition at 67o C (in bulk). Researchers have often attempted to manipulate this transition through electrochemical gating, doping, and other processes. Because strain can strongly affect the transition, we examine VO2 in comparatively strainfree powder form, though this is complicated by the difficulty of testing a powder's electronic properties. We study the transition by building small inductors and filling them with VO2 powder, then using an AC inductance bridge setup to test for changes in inductance proportional to identical, empty inductors. The resulting figures clearly show a transition at temperatures similar to those found experimentally in nanowires, though some of the more intricate details of the plots remain surprising. Notably, the inductance of the VO2 filled solenoid exhibits a peak when warming through the transition (rather than a step function change), and a dip upon cooling through the transition (again, rather than a step function change). We discuss these observations. [Preview Abstract] 

C1.00073: Flat Band Quastiperiodic Lattices Joshua Bodyfelt, Sergej Flach, Carlo Danieli Translationally invariant lattices with flat bands (FB) in their band structure possess irreducible compact localized flat band states, which can be understood through local rotation to a Fano structure. We present extension of these quasi1D FB structures under incommensurate lattices, reporting on the FB effects to the MetalInsulator Transition. [Preview Abstract] 

C1.00074: Effect of interactions on twodimensional Dirac fermions Huaiming Guo, Yongfei Jia, Ziyu Chen, ShunQing Shen, Shiping Feng Based on the twodimensional $\pi$flux model, we study the interaction effects both in nontrivial massive and massless Dirac fermions with the numerical exact diagonalization method. In the presence of the nearest and nextnearest neighbor interactions: For a nontrivial massive Dirac fermion, the topological phase is robust and persists in a finite region of the phase diagram; while for the massless Dirac fermion, chargedensity wave and stripe phases are identified and the phase diagram in the (V1,V2) plane is obtained. When the nextnextnearest neighbor interaction is further included to massless Dirac fermion, the topological phase expected in the meanfield theory is absent. Our results are related to the possibility of dynamically generating a topological phase from the electronic correlations. [Preview Abstract] 

C1.00075: ABSTRACT WITHDRAWN 

C1.00076: Substitution effect of Ir oxide with K$_{2}$NiF$_{4}$ type structure Shingo Yasuda, Kenji Kawashima, Masaaki Yoshikawa, Jun Akimitsu The ground state of Sr$_{2}$IrO$_{4}$ with the K$_{2}$NiF$_{4}$ type structure is the Mott insulator generated by the competition between the strong spinorbit coupling (SOC, $\sim$0.5eV) and weak Coulomb interaction ($U$, $\sim$0.5eV). The crystal structure of Sr$_{2}$IrO$_{4}$ consists of stacked two dimensional (2D) IrO$_{2}$ layers with canted antiferromagnetic order ($T_{\mathrm{N}} =$ 250K) and SrO layer, similar to the high$T_{\mathrm{c}}$ cuprate La$_{2}$CuO$_{4}$. We have investigated the substitution effect for Sr$_{2}$IrO$_{4}$ to confirm the influence of band filling control of Mott insulating state. We synthesized the hole doping sample of Sr$_{\mathrm{2x}}$K$_{x}$IrO$_{4}$ and electron doping sample of Sr$_{\mathrm{2x}}$La$_{x}$IrO$_{4}$. From the magnetic susceptibility data, the absolute magnetic moment of Sr$_{\mathrm{2x}}$La$_{\mathrm{x}}$IrO$_{4}$ decreases with increasing La concentration x (However, $T_{\mathrm{N}}$ value is almost constant, being independent of $x)$. The electrical resistivity data of Sr$_{\mathrm{2x}}$M$_{x}$IrO$_{4}$ (M $=$ K, La) systematically decreases with increasing $x$. These facts indicate that we succeeded in effective carrier doping to IrO$_{2}$ layer and suggest that the ground state is gradually changed toward to metallic state. [Preview Abstract] 

C1.00077: Fermi Nesting between Atomic Wires with Strong SpinOrbit Coupling Christoph Tegenkamp, Daniel L\"ukermann, Herbert Pfn\"ur, Bartosz Slomski, Gabriel Landolt, Hugo Dil Growth of 1.3~ML Pb on Si(557) results in a highly anisotropic wire ensemble structure which undergoes a 2D/1D transition when cooling as seen by surface sensitive transport measurements. In particular, the system becomes insulting in the direction across the wires. We will show that the mutual interplay between superlattice structures, band filling factors, and spinorbit coupling results in a highly correlated electronic spin and charge state. By means of spin and angleresolved photoemission spectroscopy, the spin texture close to the Fermi surface was found to be alternating and equidistant; thus, Fermi nesting occurs in between bands with the same spin helicity, giving rise to spinpolarized chargedensity waves in the direction across the wires. An outofphase superposition of both Rashba channels is manifested by an extraordinary large Rashba splitting of $\Delta k_0=0.2~\AA^{1}=g/2$, where g is a reciprocal lattice vector defined by the interwire distance and fits into the model of spindensity waves in antiferromagnetically ordered chain structures. The implications towards spinpolarized transport along the wires will be discussed. [Preview Abstract] 

C1.00078: Angle dependence of Shubnikovde Haas effect of CeOs$_4$Sb$_{12}$ and NdOs$_4$Sb$_{12}$ P.C. Ho, J. Singleton, F.F. Balakirev, M.B. Maple, T. Yanagisawa The filled skutterudite compounds CeOs$_4$Sb$_{12}$, PrOs$_4$Sb$_{12}$, and NdOs$_4$Sb$_{12}$ are respectively a 1~K antiferromagnetic (AFM) Kondo insulator, a 1.85~K unconventional superconductor, and a 1~K meanfield type ferromagnet (FM), suggesting that superconductivity in PrOs$_4$Sb$_{12}$ may result from proximity to AFM and FM quantumcritical points. Fermisurface measurements of NdOs$_4$Sb$_{12}$ and CeOs$_4$Sb$_{12}$ could therefore give insights into the pairing mechanism. A rotational skindepth measurement probe developed at pulse field facilty of NHMFL is used to detect the angle depence of the Shubnikovde Haas oscillations in single crystals of CeOs$_4$Sb$_{12}$ and NdOs$_4$Sb$_{12}$ at fields up to 60~T. The results indicate that NdOs$_4$Sb$_{12}$ has similar Fermi surfaces as those of PrOs$_4$Sb$_{12}$ and LaOs$_4$Sb$_{12}$ but the Fermi surface of CeOs$_4$Sb$_{12}$ is much different than those three compounds'. CeOs$_4$Sb$_{12}$ has similar Fermi surfaces as those of CeRu$_4$Sb$_{12}$. [Preview Abstract] 

C1.00079: Exchange interaction in lanthanides Liviu Chibotaru, Naoya Iwahara, Veaceslav Vieru Anderson's superexchange model is applied for analytical derivation of exchange interaction between total magnetic moments ${\bf J}_1$ and ${\bf J}_2$ corresponding to ground atomic multiplets of two exchangecoupled lanthanide ions. Despite the common belief that the exchange interaction is of $\sim {\bf J}_1 \cdot {\bf J}_2$ form, we find it corresponding to convolution of tensors O$_{kq}({\bf_J}_1)$ and O$_{k'q'}({\bf_J}_2)$ of ranks $k,k' \le 7$. All contributions are of the same order as the term $\sim {\bf J}_1 \cdot {\bf J}_2$ and cannot be neglected. In the case of exchangecoupled lanthanide ion (${\bf J}$) and isotropic magnetic center (${\bf S}$) the exchange interaction is described by convolutions of tensors O$_{kq}({\bf_J})$, $k=1,3,5,7$ with the spin ${\bf S}$. Among these contributions $\sim {\bf J} \cdot {\bf S}$ is not the dominant term, as was commonly assumed, hence all tensorial components should be taken into account. [Preview Abstract] 

C1.00080: Transport and magnetoresistance response of EuO$_{\mathrm{1x}}$ films fabricated by two different methods B. Goodge, L. Hellwig, M. EblenZayas EuO$_{\mathrm{1x}}$ thin films are of interest both for potential spintronic applications and for their similiarities to the colossal magnetoresistive (CMR) perovskite manganites. EuO$_{\mathrm{1x}}$ displays a semiconductor to metal transition associated with the onset of ferromagnetism and an associated large negative magnetoresistive response. Some reports suggest evidence of phase inhomogeneity in this material. We have fabricated EuO$_{\mathrm{1x}}$ films by deposition of metallic Eu and subsequent oxidation (sequential growth) and by deposition of Eu in an oxygen atmosphere (codeposition). With XRD, transport, and magnetization measurements, we compare the properties of films grown by these two methods. Both growth methods produce samples with the expected semiconductor to metal transition and large negative magnetoresistance, but we don't see evidence of phase inhomogeneity in any of the samples. [Preview Abstract] 

C1.00081: Novel Analysis Method to Extract CuNMR Parameters and their Temperature Dependence in UCu4Ni Edith Soto, Oscar Bernal We report the temperature dependence of the CuNMR parameters in a random powder of UCu4Ni as obtained by a novel method of fitting the NMR data. The method relies on the representation of the line as a sum of individual deltafunction like components and yields accurate results (to second order in perturbation theory) despite the complicated nature of the spectra. The CuNMR spectra in this material contain features arising from the response of Cu nuclei located at two inequivalent sites in the crystal structure of the system. The method works well for these anisotropically broaden NMR spectra (powder pattern), whose character is determined by magnetic and quadrupolar effects. We discuss how the different linewidth components (e.g., quadrupolar and magnetic) are separated and extracted from the fit. We also discuss how this method might work in other instances of inhomogeneously broadened NMR spectra. [Preview Abstract] 

C1.00082: Flow of Helium4 in Onedimensional Channel Clayton R. Harris, Samhita Banavar, Duk Y. Kim, Moses H.W. Chan, Jesse Bischof, John V. Badding, John Hayes, Pier Sazio Superfluidity breaks down in the onedimensional limit. However, other experiments have demonstrated superfluid flow through pores on the order of nanometers. Here we report on studying liquid helium flow through a singlehole glass capillary with internal diameters ranging from 80 to 150 nm. We observed a significant flow rate increase below the lambda transition temperature. The estimated critical velocities at low temperatures are approximately 10 m/s, which belongs to the highest group of measured critical velocities. [Preview Abstract] 

C1.00083: SUPERCONDUCTIVITY 

C1.00084: Mie plasmonpolariton modes in a 2D photonic crystal composed by superconducting cylindrical hollow rods Brayan Diaz, Jorge Mejia, Jes\'us Calero At present work we study the physical properties of localized surface plasmonpolariton modes (Mie plasmons) in a twodimensional photonic crystal composed by high temperature superconducting cylindrical hollow rods. Numerical calculations were performed by means of the finite difference timedomain (FDTD) technique by considering Drudelorentz dispersive hollow rods with an inner and outer radii R$_{1}=$0.2$a$ and R$_{2}=$0.3$a$ respectively, where $a$ corresponds to the lattice parameter. Additionally, we have calculated the field profiles for some specific modes at $\Gamma$ and X band edges within the first Brillouin zone. On the other hand, in the present work we show the conditions for Mie resonances in a single hollow rod and these results were compared with the corresponding slight dispersive modes in the case of a 2D photonic crystal. [Preview Abstract] 

C1.00085: Oxygen isotope effects in Ba$_{1x}$K$_{x}$BiO$_{3}$ hightemperature superconductors: Evidence for unconventional phononmediated pairing mechanism Nicholas Derimow, Victor Aguilar, Armond Khodagulyan, Jacob Labry, Guomeng Zhao The microscopic pairing mechanism for hightemperature superconductivity in magnetic copper and ironbased superconductors remains elusive despite tremendous experimental and theoretical efforts. The electronphonon coupling constants predicted from the local density approximation (LDA) are too small to explain hightemperature superconductivity. On the other hand, hightemperature superconductivity in nonmagnetic bismuthbased superconductors is believed to be phononmediated while the electronphonon coupling constant predicted from the LDA is also too small (about 0.30) to explain superconductivity. We report magnetic and thermal properties of the oxygenisotope exchanged Ba$_{1x}$K$_{x}$BiO$_{3}$ ($x$ = 0.37 and 0.40) hightemperature superconductors to elucidate the pairing mechanism of this material. The deduced thermodynamic critical fields, electronic specific heat anomalies, superconducting transition temperatures, and magnetic penetration depths of the $^{16}$O and $^{18}$O samples are consistent with a phononmediated pairing mechanism with the effective electronphonon coupling constant of about 1.0. We also show that the enhanced electronphonon coupling constant may arise from the lattice polaronic effect, which increases the density of states at Fermi level. [Preview Abstract] 

C1.00086: Superconductivity in the New Electroncorrelated 122layer System Ca$T_2$Ge$_2$ ($T$ = Ir, Pd, Pt) H.C. Ku, C.H. Huang, C.W. Chen, Y.B. You, M.F. Tai, Y.Y. Hsu Superconductivity were observed in the new 122layer compounds CaIr$_2$Ge$_2$ ($T_c$ = 5.4 K) and CaPd$_2$Ge$_2$ ($T_c$ = 2.5 K) with the BaFe$_2$As$_2$type bodycenteredtetragonal structure (bct, space group $I4/mmm$). For the pseudoternary Ca(Ir$_{1x}$Pt$_x$)$_2$Ge$_2$ system, superconducting transition $T_c$ decreases from 5.4 K for CaIr$_2$Ge$_2$, to 3.8 K for $x = 0.1$, 3.0 K for $x = 0.2$, 2.7 K for $x = 0.3$, 2.2 K for $x = 0.5$, and below 2 K for $x > 0.5$. In addition to the 122bct phase, xray powder diffraction pattern shows the appearance of a nonsuperconducting 122monoclinic phase (space group $P2_1$). No $T_c$ above 2 K was observed for the singlephase monoclinic compound CaPt$_2$Ge$_2$. Higher $T_c$ in the bct CaIr$_2$Ge$_2$ is due to a strong quasi2D $5d_{xz,yz}$$4p$$5d_{xz,yz}$ hybridization in the IrGeIr layer with the squeezedalong$c$axis IrGe$_4$ tetragonal crystal field and the Ir$5d$ spinorbital interaction. For the 11orthorhombic precursor (Ir$_{1x}$Pt$_x$)Ge (space group $Pnma$), $T_c$ decreases from 4.8 K for IrGe, to 3.6 K for $x = 0.1$, 2.3 K for $x = 0.2$, and below 2 K for $x \geq 0.3$, with a reported low $T_c$ of 0.4 K for PtGe. [Preview Abstract] 

C1.00087: Nerst and Seebeck magnetotransport properties of LaFeAsO from first principles Fabio Bernardini, Federico Caglieris, Ilaria Pallecchi, Pietro Manfrinetti, Alessia Provino, Gianrico Lamura, Marina Putti Iron based superconductors such as Ba(FeAs)$_2$ and LaFeAsO share with graphene the presence of Dirac cone (DC) states whose existence was confirmed by the linear dependence of the magnetoresistance behavior at low temperature. The formation of DCs is due to the presence of a spin density wave (SDW) ordered state below the the Neel temperature. The Nerst and Seebeck effects have recently proven to be sensitive probes for detecting unusual normal state properties of unconventional superconductors. In particular Nerst effect may sensitively detect Fermi reconstructions that are connected to a SDW ordered state. Here we focus on the LaFeAsO compound whose ground state exhibits static stripe order. The presence of a SDW leads to a large Nerst response. Experiments so far have not yielded a unified picture on the trend in temperature of the Nerst and Seebeck coefficients. To shed light on the experiments we computed the Nerst and Seebeck coefficients for LaFeAsO from first principles in the framework of density functional theory and BlochBoltzmann equations. Our results help to understand the trend in temperature of both Nerst and Seebeck effects. [Preview Abstract] 

C1.00088: Transient optical signature of Mott behavior in K$_{x}$Fe$_{2y}$Se$_{2}$ superconductors Wei Li, Chunfeng Zhang, Shenghua Liu, Xiaxin Ding, Xuewei Wu, Xiaoyong Wang, HaiHu Wen, Min Xiao It is a central focus whether ironbased superconductors are in close proximity to Mott behavior driven by electron correlation. The recently discovered new family of alkaline iron selenide superconductors show a resistivity hump at temperature in a range of 100250 K. However, such a metalinsulator crossover can also be viewed as parallel resistors consisted of metallic and insulating phases that are spatially separated. Here, we utilize dualcolor pumpprobe spectroscopy to study the quasiparticle dynamics with respect to Mott behavior in normal state of K$_{x}$Fe$_{2y}$Se$_{2}$ superconductors. Besides multiexponential decay recovery dynamics of photoinduced quasiparticles, a damped oscillatory component due to coherent acoustic phonons emerges when the superconducting phase is suppressed by increasing temperature or excitation power. Upon raising temperature to 150170 K, the oscillatory component diminishes together with significant enhancement of the slow decay component in the recovery traces. These results can be understood with the picture of gap opening in certain k directions, implying a vital role played by electron correlation in the ironbased superconductors. [Preview Abstract] 

C1.00089: Superconducting phase diagram of single crystal Ba$_{1x}$K$_{x}$Fe$_{2}$As$_{2}$ (0.5$\le $x$\le $1.0) Kay Fujita, Kunihiro Kihou, Kazumasa Horigane, ChulHo Lee, Jun Akimitsu Among other iron pnictides, Ba$_{1x}$K$_{x}$Fe$_{2}$As$_{2}$ is unique regarding the persistence of superconductivity in this compound up to the end member KFe$_{2}$As$_{2}$. Interestingly, the SC gap is changed with hole doping from fully opened gaps near the optimally doped region ($x=$0.4) to nodal gaps at the end member, KFe$_{2}$As$_{2}$. From these results, it is expected to show twodome structure in superconducting phase diagram. However, it has not been clarified whether twodome structure is seen or not because there are only a few repots on the phase diagram from optimally doped region to the end member. In this study, we report the result of the phase diagram of Ba$_{1x}$K$_{x}$Fe$_{2}$As$_{2}$ using the single crystals. The single crystals were synthesized by selfflux method and we succeeded in growing single crystalline samples from 0.5 to 1.0. The superconducting transition temperature ( $T_{\mathrm{c}}$ ) was determined by SQUID measurement. As increasing K concentration $x$, $T_{\mathrm{c}}$ did not follow the linear relation around $x=$0.7. The result suggests that this compound may have twodome structure. [Preview Abstract] 

C1.00090: Discovery and physical properties of new ironbased superconductors (Ca,\textit{RE})FeAs$_{2}$ Hiroyuki Yakita, Hiraku Ogino, Alberto Sala, Tomoyuki Okada, Akiyasu Yamamoto, Kohji Kishio, Tetsuya Tohei, Yuichi Ikuhara, Junichi Shimoyama, Yoshito Gotoh, Hiroshi Fujihisa, Kunimitsu Kataoka, Hiroshi Eisaki Since 2008, ironbased superconductors with various blocking layers have been reported. However, discovery of new superconductors has been still expected. Here, we report a new superconductor (Ca,\textit{RE})FeAs$_{2}$ [(Ca,\textit{RE})112]. Platelike single crystals of the new compound were successfully grown, and single crystal Xray diffraction analysis revealed the monoclinic crystal structure of the new phase. The structure is composed of two Ca(Pr) planes, antifluorite type Fe$_{2}$As$_{2}$ layer, and As$_{2}$ zigzag chain layer. HAADFSTEM images of the sample correspond well to the structure determined by the XRD analysis. Large diamagnetism suggesting 20 Kclass bulk superconductivity was observed in magnetization measurement, and superconducting transition accompanying zero resistance was also confirmed in resistivity measurement. We have also succeeded in the syntheses of (Ca,\textit{RE})112 phase with \textit{RE} $=$ La, Ce, Nd, and Sm. (Ca,La)112 phase showed higher $T_{\mathrm{c}}$ than (Ca,Pr)112 phase. [Preview Abstract] 

C1.00091: Preparation and physical properties of (M$_{1x}$Yb$_{x})$Fe$_{2}$As$_{2}$ (M $=$ Ca, Ba) single crystals S.C. Chen, K.J. Syu, W.H. Lee, Y.Y. Chen As judged by $x$ray diffraction data, single crystals in the series (M$_{1x}$Yb$_{x})$Fe$_{2}$As$_{2}$ (M $=$ Ca, Ba) with 0 \textless $x$ \textless 0.22 have been made by flux method. Magnetic and electrical properties as well as the specific heat data in the systems (M$_{1x}$Yb$_{x})$Fe$_{2}$As$_{2}$ (M $=$ Ca, Ba) investigated will be discussed. [Preview Abstract] 

C1.00092: Preparation and physical properties of Mg$_{x}$FeTe with tetragonal phase W.H. Lee, M.C. Chuang, K.J. Syu, S.C. Chen, Y.Y. Chen Unlike Fe$_{1.01}$Se, which has a superconducting T$_{c}$ near 8 K, Fe$_{1+x}$Te shows no superconductivity though it forms the same tetragonal structure with 0.06 \textless $x$ \textless 0.17. The excess Fe (2) in Fe$_{1+x}$Te not only stabilizes the PbOtype crystal structure with space group P4/nmm but also is strongly magnetic as an electron donor. According to the spin fluctuation driven scenario of superconductivity the results indicate that FeTe with doping is a likely highertemperature superconductor. In order to reduce the magnetic strength and keep the same tetragonal structure in Fe$_{1+x}$Te, in this work, we have prepared single phase samples Mg$_{x}$FeTe with $x$ around 0.1. Magnetic and electrical properties, the magnesium positions in the crystal structure as well as the possibility of highT$_{c}$ superconductivity in the Mg$_{x}$FeTe system investigated will be discussed. [Preview Abstract] 

C1.00093: Prioritized diagonal motion of electrons: Key role for high $T_c$ in the ironbased superconductors Katsuhiro Suzuki, Hidetomo Usui, Soshi Iimura, Yoshiyasu Sato, Satoru Matsuishi, Hideo Hosono, Kazuhiko Kuroki Spin fluctuation is most likely to be the pairing glue in the ironbased superconductors, but its origin remains to be under debate. The presence of disconnected electron and hole Fermi surfaces having similar shapes and sizes in the lightly carrier doped systems naturally suggests that the Fermi surface nesting is the origin of the spin fluctuation. However, recent experiments on {\it Ln}FeAsO$_{1x}$H$_{x}$ ({\it Ln}= La, Ce, Sm, Gd), where $T_c$ exceeds 50K in the largely electron doped regime despite the degraded nesting, have brought about a renewed interest on the spin fluctuation origin. In the present study, we show that the spin fluctuation in the largely doped regime is enhanced by a peculiar motion of electrons due to the tetrahedral coordination of pnictogens; the next nearest neighbor (diagonal) hoppings between iron sites dominate over the nearest neighbor ones. We argue that this ``prioritized'' diagonal motion of electrons plays a key role in the occurrence of the high $T_c$. [Preview Abstract] 

C1.00094: Muonspin rotation and magnetization studies of chemical and hydrostatic pressure effects in EuFe$_{2}$(As$_{1x}$P$_{x}$)$_{2}$ Zurab Guguchia, Alexander Shengelaya, Alexander Maisuradze, Ludovic Howald, Zbigniew Bukowski, Mamuka Chikovani, Hubertus Luetkens, Sergiy Katrych, Janusz Karpinski, Hugo Keller The magnetic phase diagram of EuFe$_{2}$(As$_{1x}$P$_{x}$)$_{2}$ was investigated by means of magnetization and muonspin rotation studies as a function of chemical (isovalent substitution of As by P) and hydrostatic pressure. The magnetic phase diagrams of the magnetic ordering of the Eu and Fe spins with respect to P content and hydrostatic pressure are determined and discussed. The present investigations reveal that the magnetic coupling between the Eu and the Fe sublattices strongly and similarly depends on chemical and hydrostatic pressure. Their impact on the occurrence of superconductivity in EuFe$_{2}$(As$_{1x}$P$_{x}$)$_{2}$ is discussed. [Preview Abstract] 

C1.00095: Annealing study of (Ca,R)Fe2As2 single crystals synthesized using Sn flux Connor Roncaioli, Tyler Drye, Shanta Saha, Johnpierre Paglione The superconducting parent compound CaFe$_{2}$As$_{2}$ displays an AFM transition at 168 K that is closely linked to an orthorhombic structural distortion. Studies on selfflux (FeAs) grown crystals have revealed the ability to tune the structural and magnetic properties of this system by annealing, resulting in a phase diagram that spans from tetragonal/orthorhombic antiferromagnetism to the nonmagnetic collapsed tetragonal phase. In this study, we investigate the effects of annealing on (Ca,R)Fe$_{2}$As$_{2}$ (R$=$rare earth) crystals grown in Sn flux in order to understand the role of growth conditions on the resultant phase diagram. We present investigations of xray, EDS, electrical transport and magnetization measurements and compare the resultant phase diagram with that of the selfflux case. [Preview Abstract] 

C1.00096: Evidence for interface superconductivity in rareearth doped CaFe$_{2}$As$_{2}$ single crystals Bing Lv, L.Z. Deng, F.Y. Wei, Y.Y. Xue, C.W. Chu To unravel to the mysterious nonbulk superconductivity up to 49K observed in rareearth (R$=$La, Ce, Pr and Nd) doped CaFe$_{2}$As$_{2}$ singlecrystals whose Tc is higher than that of any known compounds consisting of one or more of its constituent elements of R, Ca, Fe, and As at ambient or under pressures, systematic magnetic, compositional and structural have carried out on different rareearthdoped (Ca$_{1x}$R$_{x})$Fe$_{2}$As$_{2}$ samples. We have detected extremely large magnetic anisotropy, dopinglevel independent Tc, unexpected superparamagnetic clusters associated with As vacancies and their close correlation with the superconducting volume fraction, the existence of mesoscopic2D structures and Josephsonjunction arrays in this system. These observations lead us to conjecture that the Tc enhancement may be associated with naturally occurring chemical interfaces and thus provided evidence for the possible interfaceenhanced Tc in naturallygrown single crystals of Febased superconductors. [Preview Abstract] 

C1.00097: Physics in Superconductors with a Spin Density Wave: Quasiclassical Description of a twoband Model Andreas Moor, Anatoly Volkov, Konstantin Efetov Using a simple model of a twoband superconductor with a spin density wave we investigate the physics in the coexistence regime of the two order parameters, i.e., the spin density wave~(SDW) and the superconductivity~(SC). We use the quasiclassical Green's functions approach. Our findings concern, i.a., the Knight shift, the proximity and the Josephson effects, and the time and spatial dependence of the magnetic order parameter near the quantum critical point. In particular we find a solution of the stationary equation which describes a domain wall in the magnetic structure. In the center of the domain wall we find a local enhancement of~SC. Investigating the stability of a uniform commensurate SDW we obtain the values of the doping parameter at which the first order transition into the state with~${m = 0}$ takes place or to the state with an inhomogeneous SDW occurs. \\[4pt] [1] Andreas Moor, Anatoly~F.~Volkov, and Konstantin~B.~Efetov, Phys.~Rev.~B~\textbf{83}, 134524 (2011).\\[0pt] [2] A.~Moor, A~F.~Volkov, and K~B.~Efetov, Phys.~Rev.~B~\textbf{85}, 014523 (2012).\\[0pt] [3] A.~Moor, A~F.~Volkov, and K~B.~Efetov, Phys.~Rev.~B~\textbf{87}, 100504(R) (2013).\\[0pt] [4] A.~Moor, A~F.~Volkov, and K~B.~Efetov, arXiv:1309.2112 (2013) [Preview Abstract] 

C1.00098: Site specific spin dynamics in BaFe$_{2}$As$_{2}$ Priscila Rosa, Cris Adriano, Thales Garitezi, Ted Grant, Zachary Fisk, Ricardo Urbano, Pascoal Pagliuso The role of structural parameters in lowsymmetry layered systems, such as iron pnictides/chalcogenides (FePn/Ch), cuprates and some heavy fermions, has become crucial for the understanding of their properties. Here, we combine macroscopic techniques and electron spin resonance to study the spindensity wave (SDW) phase suppression due to changes of structural parameters in Ba$_{1x}$Eu$_{x}$Fe$_{2y}M_{y}$As$_{2}$ single crystals ($M =$ Co, Cu, Mn, Ni, and Ru). We show that for all transition metal substitutions, there is an increasing anisotropy and localization of the Fe 3$d$ electrons at the FeAs plane. This increasing planar xy/x$^{2}$y$^{2}$ symmetry seems to be a propitious ingredient for the emergence of superconductivity in this class of materials. [Preview Abstract] 

C1.00099: Superconductivity in the new ternary phase of the TaHfB system Lucas Eduardo Correa, Frederico Benedetto Santos, Carlos Angelo Nunes, Gilberto Carvalho Coelho, Sergio Tuan Renosto, Zachary Fisk, Antonio Jefferson da Silva Machado In the TaB binary system the TaB phase crystallizes in the orthorhombic symmetry with CrB prototype structure which displays superconducting critical temperature close to 4.0 K. To our knowledge this binary phase (CrB prototype structure) is a just stable phase in all temperature range. In this work we will show that the substitution of Ta for Hf it is able to produce a allotropic transformation from CrB to FeB prototype structure. These results represent a new pseudoternary phase in the Ta  Hf B system which is stable in high temperature. The phase found in this work present superconducting critical temperature close to 6.9 K which is sustained by specific heat, magnetization and resistivity measurements. [Preview Abstract] 

C1.00100: Superconductivity in NiTe$_{2}$ compounds interspersed with layers of Ti and Cu Frederico Benedetto Santos, Lucas Eduardo Correa, Sergio Tuan Renosto, Bruno Sanches de Lima, Renato de Figueiredo Jardim, Milton Torikachvili, Antonio Jefferson da Silva Machado NiTe$_{2}$ compound crystallizes in an hexagonal layer structure, CdI$_{2}$ prototype, where the layers of tellurium are between the layers of nickel and display some anomalies at the resistivity measurements but principally a metalinsulator like transition close to 25 K. In this work we will show that the intercalation of Copper, between TeTe van der Waals gap displacement the metalinsulator like transition until reach an unusual metal like behavior from 2.0 K to 300 K temperature range. Another hand, Titanium intercalation between TeTe van der Waals gap is able to induce superconductivity behavior with superconducting critical temperature close to 4.1 K, sustained by resistivity and magnetization measurements. [Preview Abstract] 

C1.00101: A new tetragonal superconductor withTc $=$ 3.5K Xiyu Zhu, Jianzhong Liu, YuFeng Li, Sheng Li, Huan Yang, HaiHu Wen We report the discovery of a new tetragonal superconductor at 3.5 K. Tetragonal structure has been found as a frequent platform for superconductivity, like cuprate, Iron pnictide materials. Very similar to these families, our semiconducting parent compound exhibits a charge density wave or spin density wave transition at the room temperature, according to the transport and magnetic measurements. With chemical doping, the CDW/SDW transition has been suppressed, and bulk superconductivity emerges up to 3.5K. The chemical doping also leads to a structure transition in this family. [Preview Abstract] 

C1.00102: Development and physical properties of new layered Mn pnictides Soshi Watanabe, Hiraku Ogino, Yu Katagi, Shiv Jee Singh, Akiyasu Yamamoto, JunIchi Shimoyama, Nao Takeshita, Kohji Kishio Compounds which have antifluorite Mn\textit{Pn} layer are antiferromagnetic insulators with high Neel temperature. Recent studies clarified that antiferromagnetic ordering was suppressed and insulatortometal transition was induced by carrier doping or applying pressure in Mn Arsenides, therefore Mn pnictides could exhibit various physical properties, such as superconductivity. In particular, compounds with alternate stacking of Mn\textit{Pn} layers and perovskitetype oxide layers are interesting, because this system has large flexibilities in both chemical compositions and crystal structures. In this study, we found various new Mn pnictides such as (Mn$_{2}$\textit{Pn}$_{2})$(Ba$_{3}$\textit{RE}$_{2}$O$_{5})$ [\textit{Pn} $=$ As, Sb, \textit{RE} $=$ Sc, Pr, Sm $\sim$ Lu]. (Mn$_{2}$\textit{Pn}$_{2})$(Ba$_{3}$\textit{RE}$_{2}$O$_{5})$ showed paramagnetic magnetization due to magnetization of \textit{RE} elements. Compound with shorter $a$axis length shows lower resistivity at room temperature in this system. In addition, We successfully synthesized single phase (Mn$_{2}$Bi$_{2})$(Sr$_{2}$MnO$_{2})$, which has antifluorite MnBi layers. This compound was insulating, however, resistivity greatly decreased by applying external pressure and changed to metallic behavior. This quite large dependence of resistivity on external pressure shows the possibility of the expression of the functionality such as superconductivity in corresponding compounds. [Preview Abstract] 

C1.00103: Superconductivity driven by orbital rearrangement in La$_{2}$CuO$_{4}$ Yoshiharu Krockenberger, Bennett Eleazer, Hiroshi Irie, Hideki Yamamoto La$_{2}$CuO$_{4}$ is known as the parent compound of holedoped high temperature superconductors. In La$_{2}$CuO$_{4}$, Cu and O ions form CuO$_{2}$ planes in which superconductivity takes place. It is also known that those Cu ions are octahedrally coordinated with strongly stretched octahedrons along the caxis of the unit cell owing to the JahnTeller effect. Such a system is an antiferromagnetic insulator and superconductivity is induced by hole doping, e.g. Sr or Ba. The arrangement of O around Cu can be altered into a squareplane by stateoftheart thin film growth techniques thus leaving both of the apical sites vacant. We show that the conversion from La$_{2}$CuO$_{4}$ with octahedral coordinated copper into squareplanar coordinated copper triggers an insulatortometal transition. This insulatormetal transition is induced via an orbital rearrangement that takes place due to reconfigured oxygen sublattices. More importantly, the metallic La$_{2}$CuO$_{4}$ with squareplanar coordinated copper shows a superconducting transition at 28\,K which is essentially identical to Nd$_{2}$CuO$_{4}$ or Pr$_{2}$CuO$_{4}$. These results emphasize that the parent compounds of electrondoped cuprate superconductors are superconducting \textit{per se}. [Preview Abstract] 

C1.00104: Superconductivity in a new layer compound of Ni$_{\mathrm{x}}$ZrTe$_{2}$ Pedro Henrique Bertrami D'Angelo, Orlando V. Cigarroa, Bruno S. de Lima, Zachary Fisk, Ant\^onio Jefferson S. Machado Since the discovery of superconductivity in chalcogenides in FeSe system and in iron pnictides much attention have been give for synthesis of new materials which can exhibit superconductivity. Within this context ZrTe$_{2}$ crystallizes in a CdI$_{2}$ prototype structure which posses van der Waals gap between Te bonding. In this work we will show that Ni intercalation between van der Waals gap induce superconductivity in this compound with superconducting critical temperature close to 8.0 K, which can vary with Ni content. [Preview Abstract] 

C1.00105: Multiband behavior signature in Hf0.97V0.03B2 superconductor compound Sergio Renosto, Orlando Cigarroa, Ted Grant, Carlos A. Moreira dos Santos, J. Albino Aguiar, Zachary Fisk, A. Jefferson Machado Isostructural MgB2 compounds which crystallizes in AlB2 prototype structure have been received much attention due to its potential for exhibit multiband behavior. Although there are many MB2 compounds (M  refractory metal) superconductivity it is too hard of find in the MB2 compounds. However, previous studies have been shown that Zr1xVxB2 exhibit superconducting behavior with signature of multiband. Within this context, in this work, we are showing preliminary results of the partial substitution of Hf for V in the Hf1xVxB2 with bulk superconductivity. Hall effect, magnetization, specific heat and resistivity measurements strongly suggest that this new compound represents a new example of multiband behavior. [Preview Abstract] 

C1.00106: Search for induced surface superconductivity and defect structure in ion implanted topological insulators Bi$_{2}$Se$_{3}$, Bi$_{2}$Te$_{3}$ and Iron Chalcogenides Fe (Se/Te) Single Crystals Kalyan Sasmal, Dharshana Wijesundera, Irene Rusakova, WeiKan Chu, John H. Miller, Zhong Tang, Arnold Guloy Topological superconductors represent a newly predicted phase of matter which is topologically distinct from conventional superconducting condensates of Cooper pairs. Electronic properties of Bi$_{2}$ X$_{3}$ topological insulators and Iron Chalcogenides FeX can be tuned by ion implantation. The defect structure of implanted Bi$_{2}$X$_{3}$ and FeX are studied using TEM analysis. This study presents an unprecedented route in inducing possible surface superconductivity in Bi$_{2}$Se$_{3}$, Bi$_{2}$Te$_{3}$, Fe (Se/Te) single crystals by ion implantation and the effect of ion implantation into spindensity wave (SDW) anomaly of Fe (Se/Te) single crystals studied using resistivity measurements. Due to the shallow implantation depth of the ions, the observed superconductivity is in principle confined to the surface or subsurface level, and the normal state can be recovered by thermal annealing and annealing facilitates the tuning of the carrier concentrations in Bi$_{2}$X$_{3}$, FeX crystals to allow the study of surface transport associated with the topological surface states in Bi$_{2}$X$_{3}$. [Preview Abstract] 

C1.00107: Growth of $\beta $Tungsten Films Towards a Giant Spin Hall Effect Logic Device Avyaya Jayanthinarasimham, Manasa Medikonda, Akitomo Matsubayashi, Westly Nolting, Alain Diebold, Vincent Labella Spin orbit interaction in a semiconductor and metal result in spin current transverse to a charge current, this is spin Hall effect. It was theoretically predicted by Dyakonov. et. al and J.E.Hirsch, but not until it was experimentally confirmed in 2004 by Kato, Y.K. \textit{et al}. did it attract the much attention. Recent spin Hall effect studies in metals like $\beta $Ta, $\beta $W produce spin currents strong enough to switch an adjacent magnetic layer. $\alpha $ and $\beta $ phases of Tungsten are strongly governed by film resistance, thickness, base pressure and oxygen availability. The metastable $\beta $W is known to exhibit giant spin Hall effect. Deposition conditions selective to $\beta $ phase should be used to fabricate these devices. A step wise process flow for a fully functioning device that combines the giant spin Hall effect and magnetic tunnel junction needs to be explored. This poster will present our work on fabricating and characterizing thicker tungsten films, dominated with $\beta $phase, towards a giant spin Hall Effect structures utilizing the 300 mm wafer processing facilities at CNSE. [Preview Abstract] 

C1.00108: ABSTRACT WITHDRAWN 

C1.00109: Variation of the extended $s$wave superconducting order parameter: from swave to gwave Heesang Kim, H. Chung, Nammee Kim It has been reported that the existence of fermi surface nesting may lead to strong anisotropy of order parameter even in phononmediated superconductors such as YNi$_{2}$B$_{2}$C and LuNi$_{2}$B$_{2}$C. The strong $\hat{k}$dependence may result in nodes as well, and yet the order parameter keeps the full rotational symmetry of the host metal in this case unlike the $d$wave in the cuprates. This anisotropic order parameter transforms according to the totally symmetric representation in the group theoretical point of view, and can be classified as an $s$wave. It is often called ``an extended $s$wave.'' $s+g$wave order parameter, studied in connection with the nonmagnetic borocarbides, is a good example of the extended $s$wave. Here, the effect of variation of the gap anisotropy on superconducting properties of the $s+g$wave superconductor is presenteded as a concrete example of the extended $s$wave order parameter. Starting from an $s$wave, and adding the $g$wave component, we investigate the changing shape of the order parameter, evolution of the maximum and minimum of the gap, temperature dependence of the gap amplitude, the density of states, and the specific heat. [Preview Abstract] 

C1.00110: Robustness of superconducting tendencies to disorder in the checkerboard Hubbard model Malcolm Kennett, Peter Smith The question of whether spatially inhomogeneous hopping in the two dimensional Hubbard model can lead to enhancement of superconductivity has been tackled by a number of authors in the context of the checkerboard Hubbard model (CHM). We address the effects of disorder on superconducting properties of the CHM by using exact diagonalization calculations for both potential and hopping disorder. We characterize the superconducting tendencies of the model by focusing on the pair binding energy, the spin gap, and dwave pairing order parameter. We find that superconducting tendencies, particularly the pair binding energy, are more robust to disorder when there is inhomogeneous hopping than for the uniform Hubbard model. [Preview Abstract] 

C1.00111: Strong and Weak 2D Topological Superconductivity in Hidden Quasi1D Systems Fan Yang, Hong Yao Partly motivated by the newly discovered family of bismuthbased superconductors including LaO$_{1x}$F$_x$BiS$_2$, we study possible 2D topological superconductivities (TSC) in hidden quasi1D systems with spinorbit couplings. By doing RPA calculations and renormalization group (RG) treatment, we theoretically find that in a large portion of the phase diagram with varying interaction strengths and spinorbit coupling the ground states favors superconductivity with oddparity pairing, which results in either chiral TSC or time reversal invariant weak$Z_2$ TSC. We shall discuss several ways to experimentally identify these strong and weak 2D topological superconductivity. Possible applications to the bismuthbased superconductors LaO$_{1x}$F$_x$BiS$_2$ will also be remarked. [Preview Abstract] 

C1.00112: Two orbital anaysis on the correlation between $T_c$ and the Fermi surface shape in the cuprate superconductors H. Sakakibara, K. Suzuki, H. Usui, S. Miyao, I. Maruyama, K. Kusakabe, R. Arita, H. Aoki, K. Kuroki Correlation between the Fermi surface shape and $T_c$ in the cuprates has been an issue of great interest. Experimentally, materials with more warped Fermi surfaces tend to have higher $T_c$. In our recent studies(PRL 105, 057003(2010)), we have given an explanation to this by considering a twoorbital model that explicitly takes account of the $d_{z^2}$ orbital on top of the $d_{x^2y^2}$ orbital. Namely, when the $d_{z^2}$ orbital component mixes on the Fermi surface, $d$wave pairing is degraded, while the Fermi surface becomes better nested. In our previous study, however, we had only one example of actual materials in which the $d_{z^2}$ mixture is strong, i.e., La214. In order to show that $T_c$ is indeed systematically correlated with the $d_{z^2}$ mixture, we investigate further examples, namely, Pb$_2$Sr$_2$Cu$_2$O$_6$, Pb$_2$Sr$_2$YCu$_3$O$_8$ and La$_2$CaCu$_2$O$_6$, which have relatively low $T_c$ and Fermi surfaces that are not strongly warped. Applying the fluctuation exchange approximation to the twoorbital model obtained for these materials, we show that the $d_{z^2}$ mixture does indeed reduce $T_c$. Present result endorses our conclusion that the $d_{z^2}$ orbital mixture is an important key factor for the material dependence of $T_c$ in the cuprates. [Preview Abstract] 

C1.00113: Caxis Transport Properties of DyNi2B2C W.C. Lee The resistivity along caxis $\rho $c(H,T) of DyNi2B2C have been measured with the applied magnetic field H perpendicular and parallel to caxis, 0 kG \textless H \textless 4 kG, and temperature range 2K \textless T \textless 300K. From these, the superconducting upper critical field HC2(T) curves of DyNi2B2C for the caxis were constructed for each magnetic fields and our HC2(T) curves from $\rho $c(H,T) measurement have been compared with those from previous known $\rho $ab(H,T) results. Since RNi2N2C (R $=$ non magnetic rare earth element) has isotropic electronic structure and properties, the anisotropy in HC2(T) curves of the magnetic DyNi2N2C, which has the superconducting transition temperature, TC, is lower than the N\'eel temperatures, TN, is thought to be originated from the anisotropic magnetic Dy$+$3 sublattice. [Preview Abstract] 

C1.00114: Thermomagnetic coefficients in terms of thermodynamics Andrei Sergeev, Michael Reyzer, Vladimir Mitin NernstEttingshausen coefficient in relatively strong magnetic fields is obtained and expressed via thermodynamics parameters. The relation is general and applicable to any strongly interacting systems. Contrary to a number of recent publications, this relation clearly demonstrates that the magnetization currents as well as superconducting currents do not transfer any entropy and do not participate in thermomagnetic transport. The developed machinery is applied to thermomagnetic effects in the fluctuation area. The results demonstrate that in the interacting Fermi systems the thermomagnetic coefficient is always proportional to the ratio of kT to the Fermi energy. [Preview Abstract] 

C1.00115: Dynamical JahnTeller instability in metallic fullerides Naoya Iwahara, Liviu Chibotaru The ground state of metallic fulleride K$_3$C$_{60}$ is investigated {\it ab initio} with a concomitant selfconsistent treatment of the electron correlation and the JahnTeller (JT) effect [1]. The potential energy surface has two minima with and without JT distortion. It is found that static JT instability on C$_{60}$ sites is favored when the intrafullerene electron repulsion $U > $ 650 meV. At the same time the amplitude of variations of the band energy as function of the direction of JT distortions are found to be much smaller than the energy gain from dynamical delocalization of JT deformations implying dynamical JT instability on C$_{60}$ sites. The latter develops already at $U = $ 500 meV, while for $U > $ 600 meV the amplitude of JT deformation approches the value for isolated C$_{60}^{3}$, leading to strong enlargement and complete removal of degeneracy of the LUMO band. \\[4pt] [1] N. Iwahara and L. F. Chibotaru, submitted. [Preview Abstract] 

C1.00116: Detection of charge transfers in Cooper pair box ChiaHeng Sun, PoChen Tai, JhengAn Jiang, CenShawn Wu, JengChung Chen, YungFu Chen Cooper pair in a conventional superconductor (S) is composed of two spinentangled electrons, and it may split into two nonsuperconductor (NS) regions via a process called crossed Andreev reflection. Such a spatially split entangled pair could be a quantum channel shared by two parties for quantum teleportation. However, several undesirable charge transfer processes are also involved at S/NS interfaces, such as quasiparticle tunneling, cotunneling, and ordinary Andreev reflection. In this poster we will discuss the importance of each charge transfer process in a system consisting of a superconducting island connected to two normal metal islands via two tunnel junctions, and inspect the efficiency of Cooper pair splitting in such scheme. [Preview Abstract] 

C1.00117: Study of giant proximity effect in high temperature cuprate superconductor based Josephson junctions P.K. Rout, R.K. Rakshit, R.C. Budhani While the Josephson effect in many conventional superconductors based superconductor  normal metal  superconductor junctions can be explained in term of wellknown proximity effect, a number of puzzling results have been reported for high temperature cuprate superconductor based junctions. The flow of the supercurrent in such junctions through unusually thick barriers (as thick as 100 nm) has been observed even though the superconducting coherence lengths ($\xi_N$) are of the order of few nm. Here, we present the results of our caxis oriented La$_{1.85}$Sr$_{0.15}$CuO$_4$/ La$_{1.85}$Sr$_{0.15}$Cu$_{1x}$Co$_x$O$_4$ (LSCCO)/ La$_{1.85}$Sr$_{0.15}$CuO$_4$ Josephson junctions with $x$ = 0.01, 0.02 and 0.03. The temperature dependent critical current density of the junctions clearly shows the Josephson coupling even for the LSCCO thickness of 50 nm for all $x$. We also extract the temperature dependent $\xi_N$ and the junction transition temperature, which is well above the superconducting transition temperature of the LSCCO. Our results point towards giant proximity effect in these compounds. [Preview Abstract] 

C1.00118: BKT transition for bilayer graphenebased granular superconductors Francesco Mancarella, Jonas Fransson, Alexander Balatsky We discuss a BKT phase transition for alkalidoped bilayer graphene (BLG) in the dilutedoping limit, and its dependence on the doping concentration and the stacking of the two graphene sheets, as on external conditions affecting the electronic properties, such as an applied transverse electric field, or different strains exerted on the lattice. A LangFirsov transformation of the coupling between impurities vibronic modes and graphite electrons reveals an effective local attractive pairing between electrons. A selfconsistent gap equation for BLG with intercalated impurities is then solved. We discuss the conditions for the onset of a granular superconductivity within the film, made possible by Josephson currents flowing between negative Ucenters. To ensure phase coherence over the 2D sample, we assume a random 2D distribution of impurities intercalating the BLG sheets, analyzed using a Green function approach. The tunable gatevoltage induced band gap of BLG affects the asymptotic decay of the ``Josephson coupling  distance'' characteristic for each pair of SC puddles in the sample, which results in the end in a qualitatively strong fielddependence of the relation between BKT transition critical temperature and gatevoltage. [Preview Abstract] 

C1.00119: Modeling of Biological Neurons using Superconducting Circuitry Shreeya Khadka, Oleksiy Svitelskiy, Steve Kaplan, Kenneth Segall With the goal of understanding the collective behavior of large network of neurons, we purpose a new analog method based on superconducting Josephson junction (JJ) circuitry. Through numerical simulations, we were able to show that these JJ neurons reproduce many characteristic features of biological neurons such as action potential, firing threshold and refractory period. For preliminary testing, we have designed and fabricated a superconducting chip consisting of two coupled JJ neurons, connected to each other in a closed loop. The numerical simulations of the two synchronized coupled neurons, showed a characteristic phaseflipbifurcation where the two neurons would fire either inphase or outofphase depending on their coupling strength. Thus, we are looking for the characteristic phaseflipbifurcation in the experiment also. If these encouraging observations find further confirmation, our JJ model will open a way for developing a fast and low power method of studying the dynamics of large neural networks. We would like to thank Zictools/WRSpice for layout and simulation, and Hypres Inc. for fabricating the chip. [Preview Abstract] 

C1.00120: Proximity effect in YBa$_{2}$Cu$_{3}$O$_{7\delta}$ and La$_{0.67}$Ca$_{0.33}$MnO$_{3}$ bilayers on SrTiO$_{3}$(110) Jie Li, Limin Cui, Lu Zhao, Keqiang Huang, Yirong Jin, Hui Deng, Dongning Zheng Longrange proximity effect has been reported in heterostructures of ferromagnetic halfmetal La$_{0.7}$Ca$_{0.3}$MnO$_{3}$ (LCMO) and $d$wave superconductor YBa$_{2}$Cu$_{3}$O$_{7\delta}$ (YBCO), which tends to be explained in terms of an induced spintriplet state at the interfaces. However, in most of the theoretical models the interface is often normal to CuO$_{2}$ planes, whereas in most of the experiments transport properties along $c$axis are studied. Bilayers of YBCO (20 nm) and LCMO (20 nm) were prepared by PLD technique on (110) oriented substrates, with the bottom layer either LCMO or YBCO. \textit{In situ} RHEED observations reveal that in the former the interface between LCMO and YBCO is flat. Accordingly superconductivity is completely suppressed due to the effective injection of spinpolarized electrons along the nodal direction. Whereas in the later the interface is rather rough so that superconductivity survives, although Tc is reduced and a very large transition width manifests. It was therefore suspected that in the later there exists a thin layer of LCMO at the interface with spin nonlinear configuration, which causes spinflip leading to the triplet pairing. We nevertheless recognized a positive magnetoresistance at the vicinity of Tc in either an inplane or an outofplane magnetic field. It is noted Hc$_{2}$ is remarkably higher either along the [110] or the [001] direction, when the field is along the CuO$_{2}$ plane and normal to the interface. This is, however, still compatible with the ordinary behavior of YBCO, although an anomaly in the anisotropic ratio is noticed. [Preview Abstract] 

C1.00121: Volution of upper critical field in fullerene superconductors near the Mott transition Yuichi Kasahara, Yoshihiro Iwasa, Matthew Rosseinsky, Ruth Zadik, Kosmas Prassides We here report systematic investigations of the upper critical field $H_{c2}$ of alkalimetaldoped fullerene superconductors $A_3$C$_{60}$ ($A$: Alkali metal) including Rb$_x$Cs$_{3x}$C$_{60}$ ($0 < x < 1$), which is a new series of expanded fullerene superconductors. Using Rb$_x$Cs$_{3x}$C$_{60}$, we can access the novel regime from the $T_c$ maximum to the antiferomagnetic phase even at ambient pressure. We have successfully synthesized highpurity Rb$_x$Cs$_{3x}$C$_{60}$ compounds with several Rb compositions of $x$. Determination of $H_{c2}$ has been demonstrated by rfpenetration depth measurements under pulsed magnetic field up to 62~T. With expanding lattice volume with decreasing $x$, the system approaches to the Mott insulator from the superconducting phase. We found that $H_{c2}$ continuously increases with decreasing $x$ and it reaches as large as 80~T in the lowest $x=0.35$, which is almost the verge of the Mott transition. Combining with specific heat measurements, underlying phenomena in the superconductorinsulator transition in the fullerene compounds will be discussed. [Preview Abstract] 

C1.00122: Magnetic Property in Large Array Niobium Antidot Thin Films Chen Tinghui, Kung HsiangHsi, Lee WeiLi In a superconducting ring, the total flux inside the ring is required to be an integer number of the flux quanta. Therefore, a supercurrent current can appear within the ring in order to satisfy this quantization rule, which gives rise to certain magnetic response. By using a special monolayer polymer/nanosphere hybrid we developed previously, we fabricated a series of superconducting niobium antidot thin films with different antidot diameters. The antidots form wellordered triangular lattice with a lattice spacing about 200 nm and extend over an area larger than 1 cm$^{2}$, which enables magnetic detections simply by a SQUID magnetometer. We observed magnetization oscillation with external magnetic field due to the supercurrent screening effect, where different features for large and small antidot thin films were found. Detailed size and temperature dependencies of the magnetization in niobium antidot nanostructures will be presented. [Preview Abstract] 

C1.00123: Dynamics of Bloch oscillating transistor near bifurcation threshold and its applicability for common mode rejection capability of a differential pair BOT Jayanta Sarkar, Antti Puska, Juha Hassel, Pertti Hakonen Bloch oscillating transistor (BOT) is mesoscopic current amplier based on a combination of a Josephson junction or a squid connected with a large resistor and a NIS junction. We have studied the dynamics of BOT near the bifurcation threshold [1]. This is an important feature for an amplifier as this can be utilized to improve its performance characteristics. We have measured the $IV$ characteristics of the BOT with different base currents ($I_{B})$ over a wide range of Josephson coupling energies ($E_{J})$. The current gain ($\beta )$ is found to be increasing with increasing $I_{B}$ and eventually diverging. We have found a record large $\beta =$ 50 in our experiment. In order to determine the common mode rejection ratio (CMRR) of a differential pair BOT we have used two BOTs fabricated on the same chip [2]. The common mode port is connected to the bases of the two BOTs and fed with varying voltages; simultaneously emitter currents of the two BOTs are recorded. In our experiment we found a 20dB of CMRR. [1] Sarkar et. al., Phys. Rev. B, \textbf{87}, 224514 (2013) [2] Sarkar et.al., Supercond. Sci. Technol$.$, \textbf{26}, 065009 (2013) [Preview Abstract] 

C1.00124: Temperature dependence of maximum fluxoid number in an Nb microring HeonHwa Choi, SoonGul Lee, MahnSoo Choi, JaeHyuk Choi Using a newly developed highly sensitive static force magnetometry, which enables the observation of single fluxoids, we studied the temperature dependence of the maximum fluxoid number in an Nb superconducting microring. For an 100 nmthick ring with outer and inner radius of 4.0 $\mu$m and 2.0 $\mu$m, respectively, the maximum number ranged from 100 to 40 as the temperature increases from 4 K to 7 K, showing a slope of 2 fluxoids quantum per 0.1 K in a discrete way. Thermal escape of fluxoids and its temperature dependence were analyzed with a theoretical model. [Preview Abstract] 

C1.00125: Vortex states in nanosuperconductors Liviu Chibotaru, Bart Deloof, Victor Moshchalkov The vortex states in nanoscale superconductors are investigated within generalized Bogolubovde Gennes theory. For symmetric (squareshaped) samples thermodynamically stable vortex phases form symmetryconsistent patterns and no transition to conventional Abrikosovlike vortex patterns occurs till T=0K for sizes not exceeding 25 nm. For vorticity $L=2$ a giant vortex is stabilized at temperatures in the vicinity of $T_c$, which transforms into a giant antivortex $L=2$ and four normal vortices with lowering the temperature. On the other hand, the vortex pattern for vorticity $L=3$ corresponds to an antivortex $L=1$ and four normal vortices in the whole temperature domain. The main features of GinzburgLandau phase diagram are confirmed. [1] B. Deloof, V.V. Moshchalkov, L.F. Chibotaru, Ann. Phys. 16 (2013)/DOI 10.1002. [Preview Abstract] 

C1.00126: Collective Quantum PhaseSlip Dynamics in Superconducting Nanowire Arrays Sebastian T. Skacel, Jan N. Voss, Tobias Bier, Lucas Radke, Martin Weides, Hannes Rotzinger, Hans E. Mooij, Alexey V. Ustinov$^{1}$ Superconducting nanowire arrays exhibit quantum phaseslip (QPS) phenomenon if the superconductor has a very high normalstate sheet resistance. We experimentally study QPS effects in arrays of nanowires embedded in a resonant circuit at GHz frequencies. We probe this circuit at ultralow microwave power, applied flux and mK temperatures. The nanowires are fabricated utilizing aluminium grown in a preciselycontrolled oxygen atmosphere. In this way, we aim to control the QPS rate for a given wire width. The wires are defined with conventional electron beam lithography down to a width of 20 nm. We will present the fabrication of the nanowire arrays and first microwave measurements at mK temperatures. [Preview Abstract] 

C1.00127: Magnetic field penetration depth of superconducting aluminumsubstituted Ba$_{8}$Si$_{42}$Al$_{4}$ clathrate Yang Li, Jose Garcia, Giogiovanni Franco During past years, efforts have been made to explore the superconductivity of Group IV clathrates with particular attention to the sp3 hybridized networks. In the study, we report on the superconductivity of Alsubstituted typeI silicon clathrates. Pure phase samples of the general formula Ba8Si46xAlx with different values of x were synthesized. The magnetic susceptibility measurements show that Ba8Si42Al4 is a bulk superconductor, with an onset at Tc$=$6 K. Al substitution results in a large decrease of the electronic density of states at the Fermi level, which explains the decreased superconducting critical temperature within the BCS framework. To further characterize the superconducting state, we carried out magnetic measurements showing Ba8Si42Al4 to be a type II superconductor. The critical magnetic fields were measured to be Hc1 $=$ 77 Oe and Hc2 $=$ 40 kOe. We deduce the London penetration depth 2900 {\AA} and the coherence length 90 {\AA}. Our estimate of the electronphonon coupling reveals that Ba8Si42Al4 is a moderate phononmediated BCS superconductor. [Preview Abstract] 

C1.00128: Thermodynamic and electronic properties of superconducting state of KM$_{\mathrm{2}}$ (M $=$ Sn, Pb) with the MgZn$_{\mathrm{2}}$type structure Shota Miyazaki, Kenji Kawashima, Daiki Hyakumura, Ryutaro Matsumura, Masaaki Yoshikawa, Jun Akimitsu We discovered new superconductors of KM$_{\mathrm{2}}$ (M $=$ Sn, Pb) with the MgZn$_{\mathrm{2}}$type (C14) structure (Laves phase) using the high pressure / temperature technique. The superconducting transition temperature ($T_{\mathrm{c}})$ is to be $T_{\mathrm{c}} \quad =$ 3.2 K for KSn$_{\mathrm{2}}$ and $T_{\mathrm{c}} \quad =$ 3 K for KPb$_{\mathrm{2}}$ (These samples include small impurity phase of Sn ($T_{\mathrm{c}} \quad =$ 3.7 K) and Pb ($T_{\mathrm{c}} \quad =$ 6.7 K)). In order to determine the superconducting parameters, we have performed the magnetic susceptibility measurement. The magnetization versus magnetic field curves of KM$_{\mathrm{2}}$ at 1.8 K shows a typical typeII superconducting behavior. From the density of state (DOS) calculation using the WIEN2K, the main contribution of DOS near the Fermi level ($E_{\mathrm{F}})$ is Sn (Pb) orbitals. In particular, $p$orbitals of Sn (Pb) are dominant, indicating that the $p$orbital of these atoms plays an important role for the superconducting state in KM$_{\mathrm{2}}$ [Preview Abstract] 

C1.00129: Zr$_{5}$Sb$_{3}$first Superconductor in the Mn$_{5}$Si$_{3}$type system Bing Lv, X.Y. Zhu, B. Lorenz, F.Y. Wei, Y.Y. Xue, Z.P. Yin, G. Kotliar, C.W. Chu Systematic exploration for superconductivity in the Zr$_{5}$X$_{3}$ (x$=$Sb, Sn, Ge, Ga, and Al) system have been carried out, and we report the discovery of superconductivity at 2.3 K in Zr$_{5}$Sb$_{3}$, the first superconducting member in the large compound family of the Mn$_{5}$Si$_{3}$structure type. Transport, magnetic, and calorimetric measurements clearly demonstrate the bulk superconductivity for the Zr$_{5}$Sb$_{3}$ and band structure calculations suggest it to be a possible phononmediated BCS superconductor, with a relatively large density of states at the Fermi level associated with the delectrons of Zr and substantially larger electronphonon coupling compared to the Sn counterpart compound Zr$_{5}$Sn$_{3}$. Detailed doping studies have shown that superconductivity in Zr$_{5}$Sb$_{3}$ is rather robust with Hf and Ysubstitution of Zr, but suppressed by Tisubstitution. It is also suppressed by interstitial filling in Zr$_{5}$Sb$_{3}$Z by Z $=$ Sb, C, or O. [Preview Abstract] 

C1.00130: Superconductivity in a new noncentrosymmetric compound of YCoC$_2$ composition Orlando V. Cigarroa, Sergio T. Renosto, Ted Grant, Zachary Fisk, A. Jefferson S. Machado Superconductivity in compounds whose crystal structure lacks inversion symmetry are known to display intriguing properties that deviate from conventional BCS superconducting behavior. Here we report magnetization, resistivity, and heat capacity measurements on polycrystalline samples of noncentrosymmetric YCoC$_{2}$, showing clear evidence of bulk superconductivity with a critical temperature of T$_{\mathrm{c}}=$4.2 K. Interestingly the specific heat of the superconducting state deviates from conventional exponential temperature dependence, which is suggestive of possible unconventional superconducting behavior in YCoC$_{2}$, similar to that seen in the isostructural and isoelectronic superconductor LaNiC$_{2}$. Besides, these results strongly suggest that this material is a new multiban [Preview Abstract] 

C1.00131: Global Phase Diagram in Layered Organic Conductors Yan Chen, Yaowu Guo Layered organic superconductors serve as model systems for Mott physics with geometrical frustration. The global phase diagram of such system is obtained by using Gutzwiller variational method to study a Hubbard model including a spin exchange coupling term. Five possible candidates of ground state are obtained respectively, including a spin liquid insulating state at large onsite Coulomb repulsion U and large lattice frustration t'/t, an antiferromagnetic state at large U and small t'/t , two Gossamer superconducting states at medium U with either gapless d$_{x2y2}$wave (small t'/t) or gapped d$+$idwave symmetry (large t'/t) , and a metallic Fermi liquid state at small U. Moreover, we study the evolution of double occupancy number d in terms of different U and t'/t parameters mimicking the pressure effect. Our results are qualitatively consistent with main experimental results in organic superconductors. /abstract Billing ID: 814549 \newline Member~I [Preview Abstract] 

C1.00132: SEMICONDUCTORS 

C1.00133: Study of structural and optical properties of Al doped ZnO nanoparticles Mallika A N, Ramachandra Reddy A This paper reports on the structural and optical properties of Al doped ZnO nanoparticles prepared through solgel method using poly vinyl alcohol as chelating agent. Al was effectively doped in ZnO with concentrations up to 6 atomic percent concentrations (at. {\%}). Xray diffraction (XRD) results revealed that all the samples do not have impurity phase indicating hexagonal wurtzite structure of ZnO formed, the average crystallite sizes were decreased with increasing Al concentrations. A compressive strain was induced with Al doping and was calculated with WH plot analysis. The morphology of all the samples was studied from Field Emission Scanning Electron Microscope (FESEM). The energy band gap of the Al doped samples was estimated from UVVis spectrum showed an overall increase. The presence of functional groups and chemical bonding of ZnO with Al doping was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) spectra, and in addition to this, the photoluminescence (PL) properties of Al doped ZnO nanoparticles were studied. [Preview Abstract] 

C1.00134: The importance of inhomogeneities in hydrogenated amorphous silicon Satish Agarwal We shall discuss how the heterogeneities present in hydrogenated amorphous silicon (aSi:H) can be taken into account by considering the long range potential fluctuations (LRPF), arising from them. Using these ideas we try to understand several challenging puzzles, some of them remaining unresolved till now. These range, from why undoped aSi:H is ntype, to why the light soaking (LS) degrades boron doped aSi:H films faster than the undoped or the phosphorous doped films, and why hole injection favors larger degradation than electron injection. Also, the failure of reciprocity and the saturation of the number of dangling bonds created by LS at the low value of about 10$^{17}$ cm$^{3}$ can be explained. The improved stability of aSi:H containing ncSi has been attributed\footnote{S.C. Agarwal, Philos. Mag. (2013) DOI: 10.1080/14786435.2013.824626} to the LRPF assisted diffusion of photo carriers to ncSi and recombination there. These and other similar observations will be taken up. [Preview Abstract] 

C1.00135: Fabrication of High InContent InGaN/GaN QuantumWell for LightEmitting Diodes ChenChi Yang, Ikai Lo, ChiaHsuan Hu, YingChieh Wang, YuChiao Lin, ChengDa Tasi, ShuoTing You We have grown In$_{\mathrm{x}}$Ga$_{\mathrm{1x}}$N/GaN multiple quantumwells (MQWs) thin films with different In contents (x $=$ 0.194 and 0.331) on sapphire substrate by using plasmaassisted molecular beam epitaxy. 1x1 mm$^{\mathrm{2}}$ size substrate was used in this study, and InGaN/GaN multiple quantumwells (MQWs) structure was grown between the ntype and ptype GaN cladding layers. First of all, we deposited Ni/Au alloy for ptype contact by ebeam evaporation to avoid the damage of ptype GaN. Secondly, we constructed ntype GaN by inductive couple plasma etcher (ICPEtcher). Finally, we deposited Ti/Al for ntype contact by ebeam evaporation. The optical properties of the samples were analyzed by photoluminescence (PL) and electroluminescence (EL) measurements at room temperature. The comparison of optical properties between PL and EL of the samples is under investigation. [Preview Abstract] 

C1.00136: Growth and Characterization of Homoepitaxial GaN on Nface GaN Freestanding~Substrate by PlasmaAssisted MolecularBeam Epitaxy ChengDa Tsai, Ikai Lo, WeiI Lee, ChuoHan Lee, YingChieh Wang, ChiaHsuan Hu, ChengHung Shih, ChenChi Yang, YuChiao Lin, ShuoTing You As compared to the commercial GaN based LED with the Gaface GaN substrate, the GaN film grown along Nface GaN has been considered to have better current injection efficiency for GaN pn junction. In this paper, we have studied the growth of GaN epilayer on Nface GaN freestanding substrate. The Nface GaN freestanding substrate was prepared by hydride vapor phase epitaxy and its full width at half maximum is 469.2 arcsec by Xray analysis. The homoepitaxial GaN samples were grown atop the prepared Nface GaN freestanding substrate by plasmaassisted molecularbeam epitaxy under different growth conditions. The homoepitaxial GaN samples were characterized by the insitu reflection highenergy electron diffraction, Xray diffractometry, field emission secondary electron microscope, and atomic force microscope. In addition, the optical properties of the samples were analyzed by polarizationdependent photoluminescence. [Preview Abstract] 

C1.00137: ThreeDimensional Multiscale Modeling of Stable Intermediate State Formation Mechanism in a Single Active Layer Phase Change Memory Cell Onur Dincer, Ibrahim Cinar, Vedat Karakas, Ozgur Burak Aslan, Aisha Gokce, Barry Stipe, Jordan A. Katine, Gulen Aktas, Ozhan Ozatay Phase change memory (PCM) appears as a potential memory technology with its superior scalability which could be enhanced by a boost in storage density via multiplebit per cell functionality. Given the large contrast between set and reset states of a PCM cell it is yet unclear whether it is possible to create intermediate logic states reproducibly and controllably in a device with a single active phase change layer. Here we report the results of a 3D finite element model that pinpoints the direct effect of current distribution and the indirect effect of device top contact fabrication induced defects through modification of phase change kinetics (crystallite nucleation and growth rates) on stabilization of intermediate states. A comprehensive picture of the electrical, thermal and phase change dynamics is obtained using a multiphysics approach. Our study shows that homogeneous and heterogeneous phase transition can be induced in the active region such that nonuniform temperature distribution and modification of switching dynamics with various contact shapes and sizes play a major role in the stabilization of a mixed phase state. [Preview Abstract] 

C1.00138: InAs 2DEGs:What's the gfactor? B.D. McCombe, Mehdi Pakmehr, A. Khaetskii, Olivio Chiatti, S.F. Fischer, S. Buchholz, C. Heyn, W. Hansen, M. Cahay, R.S. Newrock, Nikhil Bandari Interest in spinorbit effects in semiconductors has led us to study the electron gfactor in quasi2DEG InAs samples. We have made magnetotransport and photoresponse (PR) measurements on InAs QW structures in magnetic fields up to 10 T. THz cyclotron resonance (CR) is manifested in PR as a resonant envelope of the amplitude of quantum oscillations, which show clear spinsplitting (for lower mobility samples) down 4T, while direct R\textunderscore xx measurements show no spinsplitting up to 9T. R\textunderscore xx oscillations in a higher mobility sample show wellresolved spinsplittings over a range of fields as does the PR. We have simulated the data with a theoretical expression for 2DEG SdH oscillations (coupled with CR resonant carrier heating for the PR) and extracted gfactors from fits. We also used a different (commonly used) method, SdH oscillations vs. tilt angle of the field to extract gfactors from the angle at which the SdH frequency doubles. We find very large gfactors from fits to R\textunderscore xx and PR (14  20), but gfactors 23 times smaller for these same samples from tilted field experiments (close to estimated band gfactors). These results are discussed in terms of exchange effects. [Preview Abstract] 

C1.00139: Topological transitions of spin geometric phases in quantum rings Henri Saarikoski, Enrique Vazquez, Diego Frustaglia, Junsaku Nitta, Gen Tatara Topological phenomena in condensed matter physics have recently attracted much interest. In spintronics, topology of the path that a spinsteering field subtends is related to the geometric phase the spin acquires. Geometric phase of spin is tolerant against noise and imperfections in the system which offers robust ways for spin manipulation [1]. We study topological transitions in the spin geometric phase in quantum rings. These transitions are predicted to give a discontinuous change in the current through the system [2]. We show that decoherence due to time reversal asymmetry and diabatic band transitions change this picture. We find a smoothly changing current in numerical calculations and 1D exact models. In ballistic systems AharonovCasher conductance oscillations vanish in the regime where the geometric phase drops to zero. We discuss possible signatures of topological transitions in the experimental data.\\[4pt] [1] F. Nagasawa et al. Nat. Commun. 4:2526 (2013).\\[0pt] [2] Y. LyandaGeller, Phys. Rev. Lett. 71, 657 (1993). [Preview Abstract] 

C1.00140: Spin filtering for various geometries of inhomogeneous magnetic field Nammee Kim, Heesang Kim, Jinwoo Kim Based upon a hybrid superconductor/semiconductor structure consisting of twodimensional electron gas and a surface superconducting mask on top, we investigate the properties of the spindependent ballistic transport, theoretically. Landau approach is adopted for the calculation of spin transport properties for various geometries of inhomogeneous magnetic field. In this study, we mainly concentrate on the difference in their efficiency of spin filtering with spinorbit interaction known as the Rashba effect considered. [Preview Abstract] 

C1.00141: Maximum values of the conserved spin and orbital Hall conductivities in the generic klinear spinorbit coupled semiconductor systems TzuChen Lin, ChienHuang Lee, TsungWei Chen The effective conserved spin current is composed of the conventional spin current and the torque spin current. We analytically calculate the intrinsic spin Hall conductivity in the generic klinear spinorbit coupled semiconductor systems by using Kubo formula. We find that the magnitude of the conventional spinHall conductivity depends on the orientation of the system. Furthermore, the conventional spinHall conductivity has a maximum value when the spin current occurs in the direction with the smallest band splitting, which is shown to be the manifestation of the Berry curvature. However, when the torque spinHall conductivity is considered, the resulting total spinHall conductivity reaches a maximum when the spin current occurs in the direction with the largest band splitting. We also calculate the conventional and torque orbital Hall conductivities in the generic klinear systems and show that the sum of spinHall and orbital Hall conductivities vanishes in the systems with conservation of total angular momentum. [Preview Abstract] 

C1.00142: ABSTRACT MOVED TO H1.00328 

C1.00143: Efficient luminescent center by codoping of (Eu, Mg, O) to GaN Akira Masago, Tesuya Fukushima, Hiroshi KatayamaYoshida From a theoretical point of view, we propose that GaN codoped with Eu, Mg, and O is a good photoluminescent material. We guess that codoping of O besides Eu and Mg to GaN can promote the recombination of excitons, where the compound of Eu and Mg codoped GaN has been already reported with high validity of light emitting in experiments. [1] In this work, we used the Vienna abinitio simulation package (VASP). [2] As a result, we found that the three impurity elements tend to assemble themselves energetically in the host crystal GaN, though the two elements (Eu and Mg) do not. Moreover, the complexes of EuOMg generate an area with a band gap that is narrower than the host crystal. This means that the complexes can attract and trap excitons that are generated around the complexes. Consequently, most of excitons must recombine there and convert into light efficiently. [1] D. Lee, A. Nishiwaka, Y. Terai, et al., Appl. Phys. Lett. 100 (2012) 171904. [2] G. Kresse and D. Joubert, Phys. Rev. B 59 (1999) 1758. [Preview Abstract] 

C1.00144: Raman scattering investigations on Co and Mn doped ZnO epitaxial films: local vibration modes and defect associated ferromagnetism Qiang Cao, Guolei Liu, Shishen Yan, Liangmo Mei The studies of local vibration modes (LVMs) of Co or Mn substitution in wurtzite ZnO lattice have been rather limited, and evolution of LVM bound defects as well as associated ferromagnetism are still poorly understood.In this paper, Raman scattering spectroscopy has been performed on high quality Co and Mn doped ZnO epitaxial films, which were grown on $Al_{2}O_{3}$(0001) by oxygenplasma assisted molecular beam epitaxy. Raman measurements revealed two local vibration modes (LVMs) at 723 and 699 cm$^{?1}$ due to the substitution of Co$^{2+}$ in wurtzite ZnO lattice. The LVM at 723 cm$^{?1}$ is found to be an elemental sensitive vibration mode for Co substitution. The LVM at 699cm$^{1}$ can be attributed to enrichment of Co$^{2+}$ bound with oxygen vacancy, the cobalt?oxygen vacancy?cobalt complexes, which associated with ferromagnetism. It reveals two competitive local vibration modes (LVMs) at 712 and 523 cm$^{1}$ due to the substitution of Mn ions in wurtzite ZnO lattice. The LVM at 712cm$^{1}$ is found to be an elemental vibration mode of Mn substitution in wurtzite ZnO lattice, while the LVM at 523cm$^{1}$ can be attributed to the local vibration mode of acceptor bound Mn substitution in wurtzite ZnO lattice. [Preview Abstract] 

C1.00145: Atom Probe Tomography Analysis of GalliumNitrideBased LightEmitting Diodes Ty J. Prosa, David Olson, A. Devin Giddings, Peter H. Clifton, David J. Larson, Williams Lefebvre Thinfilm lightemitting diodes (LEDs) composed of GaN/In$_{x}$Ga$_{1x}$N/GaN quantum well (QW) structures are integrated into modern optoelectronic devices because of the tunable InGaN bandgap enabling emission of the full visible spectrum. Atom probe tomography (APT) offers unique capabilities for 3D device characterization including compositional mapping of nanovolumes (\textgreater 10$^{6}$ nm$^{3})$, high detection efficiency (\textgreater 50{\%}), and good sensitivity [1]. In this study, APT is used to understand the distribution of dopants as well as Al and In alloying agents in a GaN device. Measurements using transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) have also been made to improve the accuracy of the APT analysis by correlating the information content of these complimentary techniques. APT analysis reveals various QW and other optoelectronic structures including a Mg pGaN layer, an Alrich electron blocking layer, an Inrich multiQW region, and an Inbased superlattice structure. The multiQW composition shows good quantitative agreement with layer thickness and spacing extracted from a high resolution TEM image intensity analysis. [1] T. F. Kelly and D. J. Larson, Annual Reviews of Materials Research 42 (2012) 1. [Preview Abstract] 

C1.00146: Ab initio study of \{In,Ru,Ir\}doped CeO2 Roberto NunezGonzalez, Ricardo Rangel, Donald H. Galvan, Alvaro PosadaAmarillas Structural and electronic properties of ceria doped with Indium, Ruthenium and Iridium were calculated using the FullPotential Augmented Plane Waves with local orbital Method (APW+lo), within the Density Functional Theory. DFT calculations were performed for 1x1x2 and 2x2x2 supercells using GGA and hybrid exchangecorrelation potentials. For each cell the atoms were relaxed by minimizing forces. Geometric and band structure results are examined and a comparison with pure ceria structural and electronic properties is performed. [Preview Abstract] 

C1.00147: Production of silicon modified to have enhanced infrared absorption E. Weld, R. Ayachitula, K. de La Harpe, L. Brandt, M. Chilton, R.J. Knize, B.M. Patterson We demonstrate the enhanced optical properties of silicon microstructures formed by irradiation of a silicon wafer by a modulated continuous wave (CW) laser beam in the presence of SF$_{6}$. The microstructures are doped with about 0.6{\%} sulfur, which extends the absorption well below the 1.1um bandgap of crystalline silicon and results in a 60{\%} increase in the absorption of infrared radiation. The microstructured silicon produced using microsecond pulses of CW light demonstrates comparable infrared absorption enhancement to black silicon made using more expensive and complicated laser systems. This enhanced absorption as a result of these microstructures has been studied over the past decade in an effort to create high responsivity detectors and night vision goggles and improve the efficiency of solar cells. We will also discuss additional methods that allow tunability and scalability in the production of silicon modified to demonstrate increased infrared absorption. [Preview Abstract] 

C1.00148: Confinement of an electron with effective mass depending on its position inside a semiconductor Al$_{\mathrm{x}}$Ga$_{\mathrm{1x}}$As medium Martin Eduardo MolinarTabares, Carlos FigueroaNavarro, Lamberto CastroArce, Julio C\'esar CamposGarc\'Ia The confinement of an electron inside a twodimensional semiconductor structure of Al$_{\mathrm{x}}$Ga$_{\mathrm{1x}}$As which has been deposited on a substrate is studied. In the structure, that has a circular form with radii $\rho_{\mathrm{0}}$, the concentration x in a point depends of the distance from this point to the center of the circumference, and this dependence appears in the potential energy of the electron and in its effective mass too. Considering different forms in which concentration x varies respect $\rho $, we solve the Schr\"{o}dinger equation in polar coordinates ($\rho $,$\theta )$ using a basis formed with the first zeros of Bessel functions of different order m. Taking into account in the Schr\"{o}dinger equation the dependence of the effective mass of the electron on its radial coordinate $\rho $, we work a numerical solution and we obtain the ground state energy, the energy for some excited states, and the probability density of those states. [Preview Abstract] 

C1.00149: Effect of Gold Roughness on Growth of Copper Phthalocyanine Joshua Corona, Carlos Garcia, Thomas Gredig Metallophthalocyaninebased thin films have found diverse applications, in fieldeffect transistors, gas sensors, and photovoltaic devices. The device performance and electrical properties depend on the orientation of the planar molecule with respect to the substrate. It had been previously found that the molecular plane adheres parallel to a metallic surface, whereas the metalcenters attach to themselves on insulating substrates forming a standing configuration. Here, the effect of gold roughness is examined using atomic force microscopy (AFM) and xray diffraction (XRD). Samples were codeposited at room temperature with 20~nm of CuPc ensuring identicall conditions. The Au roughness was varied by depositing it either onto Cr or Si and by modifying the Au thickness from 12~nm to 50~nm. The change in thickness for the Au/Si substrates caused a change in the roughness of the CuPc from 5.8~nm to 2.3~nm. Crystallographic peaks from xray diffraction showed a crystalline peak of 13.0~\AA~at 6.8$^o$ for all samples. The surface morphology and grain size, however, was unaffected. [Preview Abstract] 

C1.00150: Interface engineered resistive switching in Ag/SrTiO$_{3}$/Nd$_{0.7}$Ca$_{0.3}$MnO$_{3}$/YBa$_{2}$Cu$_{3}$O$_{7}$ devices Zhongwen Xing, Grace Lin Effects of buffer layer of SrTiO$_{3}$ (STO) on the room temperature resistive switching devices of Ag/Nd$_{0.7}$Ca$_{0.3}$MnO$_{3}$/YBa$_{2}$Cu$_{3}$O$_{7}$ (Ag/NCMO/YBCO) are investigated for the first time. It is found that the insertion of the STO buffer layer into the interface between Ag and NCMO greatly increases the electricfieldinducedresistance (EPIR) ratio. The device can be switched onandoff from a higher to lower resistance state with a ratio of 253{\%} (405{\%}) at the pulsed voltage of $\pm$ 1.5 volt ($\pm$ 3.0 volt). The enhancement of EPIR ratio is attributed to the modification of the Ag/NCMO interface and the electricpulse driven oxygen vacancy. [Preview Abstract] 

C1.00151: Structural Properties of Gold Thin Films Deposited on various Substrates by RF Magnetron Sputtering Moniruzzaman Syed, Caleb Glaser, Michael Schell, Indrajith Senevirathne In this study, Gold (Au) thin films were deposited on glass (SiO$_{2})$ and silicon (100) substrates at room temperature (RT) in an argon (Ar) gas environment as a function of sputtering time (Tsp). The structural properties of Au films have been studied using an Atomic Force Microscope (AFM). The results of this study indicate that the structural properties of the deposited Au film are related to the conductance of the substrate. AFM micrographs of Au films show that the films on nonconductive substrates show higher coalescence for longer sputtering times. Au films deposited on conductive silicon substrates show structures that show microvoids and to homogenous structures as the sputtering time increases. On the other hand, gold films deposited to nonconductive glass substrates showed homogenous structures that changed to cluster and islandtype as a function of sputtering time. [Preview Abstract] 

C1.00152: Bismuth adsorption on Ge(001) Maria Longobardi, Renan Villarreal, Christoph Renner Bismuth (Bi) is a semimetal with unique electronic properties due to its highly anisotropic Fermi surface, long Fermi wavelength and small effective electron mass. Moreover, Bi nanostructures have attracted much attention for their interesting physical properties and they are expected to exhibit quantum confinement effects resulting from the finite size. It has been reported that bismuth thin films and nanowires with diameter below 50 nm show a semimetalsemiconductor transition. In the special case of Si(001) 2x1 substrate Bi selfassembles in micrometer long almost defect free atomic nanolines (1). Here, we report a low temperature STM/STS study of the Bi adsorption on Ge(001) 2x1 substrate. The geometric and electronic structure of different Bi nanostructures are discussed as function of the bismuth coverage and the temperature of germanium substrate during Bi deposition. \\[4pt] (1) J. H. G. Owen, F. Bianco, S. A. Koster, D. Mazur, D. R. Bowler, and Ch. Renner, Appl. Phys. Lett. 97, 093102 (2010). [Preview Abstract] 

C1.00153: FullBand ParticleBased MonteCarlo Simulation with Anharmonic Corrections for Phonon Transport in IIIN Nanostructures Sasi Sundaresan, Thushari Jayasekera, Shaikh Ahmed Monte Carlo based statistical approach to solve Boltzmann Transport Equation (BTE) has become a norm to investigate heat transport in semiconductors at submicron regime, owing to its ability to characterize realistically sized device geometries qualitatively. One weakness of this technique is that the approach predominantly uses empirically fitted phonon dispersion relation as input to determine the properties of phonons and predict the thermal conductivity for a specified material geometry. The empirically fitted dispersion relations assume harmonic approximation, thereby failing to account for thermal expansion, effects of strain on spring stiffness, and accurate phononphonon interactions. To account for the anharmonic contributions in the calculation of thermal conductivity, in this work, we employ a coupled molecular mechanicsMonte Carlo (MMMC) approach. The atomisticallyresolved nondeterministic approach adopted in this work is found to produce satisfactory results on heat transport and thermal conductivity in both ballistic and diffusive regimes for IIIN nanostructures. [Preview Abstract] 

C1.00154: Effects of Contact Resistances in Determining the Efficiency of Nanostructured Thermoelectric Coolers Afsana Sharmin, Abu Sadeque, Vamsi Gaddipati, Shaikh Ahmed Sitespecific thermoelectric cooling in semiconductor materials is among the most promising approaches for the mitigation of onchip hot spots resulting from the decreasing feature sizes and faster switching speeds of electronic components. The efficient usage of thermoelectric devices for hotspot cooling requires investigation of appropriate properties such as higher figureofmerit, integration of these devices with electronic package, and remedy of various obstacles such as parasitic contact resistances. A multiscale simulation model has been developed to investigate the steadystate operation of nanowire based thermoelectric devices for hotspot cooling considering the effects of thermal and electrical contact resistances. The results suggest that active hotspot cooling of as much as 20\textordmasculine C with a high heat flux is achievable with Bi$_{2}$Te$_{3}$ nanowire based thermoelectric coolers. However, it has been observed that thermal and electrical contact resistances, which are large in nanostructures, play a critical role in determining the cooling range and lead to significant performance degradation of these novel reduceddimensionality coolers. [Preview Abstract] 

C1.00155: Nanosale Effects in Junctionless FETs Abdussamad Muntahi, Sameer AlSibiani, Shaikh Ahmed We investigate the performance of multigate junctionless FETs in the nanoscale regime of operation, and show how thinchannel, gate type, quantum sizequantization, random dopant fluctuations, and selfheating, affect the recentlyproposed junctionless FET characteristics and compare to a junctioned FET counterpart. A 3D fully \textit{atomistic} quantumcorrected Monte Carlo device simulator has been used in this work. The essential bandstructure parameters (such as bandgap, effective mass, and the densityofstates) have been computed using a 20band nearestneighbour \textit{sp}$^{3}d^{5}s^{\ast }$ tightbinding scheme. Quantum sizequantization effects have been accounted for via a \textit{parameterfree} effective potential scheme (and benchmarked against the NEGF approach as implemented in the \textit{nanoFET }toolkit, in the ballistic limit). To treat electronion and electronelectron interactions, the simulator implements a realspace corrected Coulomb electron dynamics (ED) scheme. Results on $I_{ON}$/$I_{OFF}$, S, DIBL, $r_{0}$, $g_{m}$, $f_{T}$, $V_{TH}$ variation, RTS, and current degradation due to selfheating will be presented. [Preview Abstract] 

C1.00156: Fabrication of a ringshaped graphene device on boron nitride crystal Seong Jang, Eunseong Kim Even though Andreev reflection in graphene [1] intrigued much attention due to its specular aspect which is different from other materials, no experimental result has shown such specular reflection so far. Recently, it is predicted that the period of magnetoresistance oscillation in a ring shaped graphene can distinguish the type of Andreev reflection in a device [2]. We fabricated a graphene device on boron nitride crystal in order to avoid charge inhomogeneity and low mobility in the device, which allows comparable transport properties to that of suspended graphene [3]. Graphene on BN is a promising design because BN crystal can support a narrow and punched graphene device which easily collapses in suspended structure. We will report how to fabricate this device with electron beam lithography and plasma etching. \\[4pt] [1] C. W. J. Beenakker, Phys. Rev. Lett., 97, 067007 (2006) \\[0pt] [2] J. Schelter et al., Phys. Rev. Lett., 108, 106603 (2012)\\[0pt] [3] C. R. Dean et al., Nat. Nanotechnol., 5, 722726 (2010) [Preview Abstract] 

C1.00157: Structural evolution during crystallization of supercooled niobium: \textit{ab initio} molecular dynamics simulations Tekalign T. Debela, H.Y. Lu, X.D. Wang, P.Q. Cao, D.X. Zhang, J.Z. Jiang We report on \textit{ab initio} molecular dynamics simulations study of crystallization in metallic niobium supercooled liquid. Using various structural analysis methods including bond orientational order analysis, a scheme of crystallization process is revealed. Various locally favored clusters act as precursors for nucleation. Our findings reveal that crystallization is not primarily due to density fluctuations; rather it is caused by development of extended structured regions of high orientational order which gradually solidify. This crystallization behavior is consistent with that recently reported for hard sphere (colloidal) as well as soft sphere (Gaussian core model) systems. [Preview Abstract] 

C1.00158: The role of hydrogen on the structural properties of nanocrystalline silicon Alessandro Mattoni Hydrogenated nanocrystalline silicon (ncSi:H) is an emerging thinfilm photovoltaic material$^{\, }$that combines advantages of silicon (cSi), like high carrier mobility, with less expensive production methods of amorphous silicon (aSi). Among several processing issues, hydrogenation is critically in affecting the structural and electronic properties of ncSi[1]. Here, we report molecular dynamics theoretical results on the effect of dissolved hydrogen on the thermally induced recrystallization[2] of nanocrystalline silicon. The recrystallization rate decreases exponentially with hydrogenation with a tendency of H atoms to outdiffuse to the crystal phase at low concentration and forming immobile SimHn hydrides at higher concentration[3]. The tendency of H to segregate in the amorphous enables quantum confinement phenomena with the holes localized within the crystal grains. The possibility to tune the electronic gap of the material by the grains size is showed by semiempirical and ab initio electronic structure calculations on large scale atomistic models[4].[1] L. Bagolini et al. PRL 104, 176803 (2010);[2] A. Mattoni et al., PRL 99, 205501 (2007); 78 075408 (2008); [3] G. Fugallo and A. Mattoni, submitt (2013); [4] A. Mattoni et al., 79, 245302 (2009); [Preview Abstract] 

C1.00159: Quasienergy resonance in a dynamicWannierStark ladder Yuya Nemoto, Kenichi Hino, Nobuya Maeshima A continuum effect of a dynamic WannierStark ladder driven by a cw laser is examined in terms of an excess density of states (EDOS), corresponding to the lifetime of a resonance state [1]. It is mathematically shown that EDOS is governed by three different physical mechanisms, namely, the singlechannel resonance mechanism, the multichannel nonresonance mechanism, and the multichannel resonance mechanism. The last mechanism becomes more important with increasing laser amplitude F$_{\mathrm{ac}}$. The effect of the interchannel interaction is maximized when the ratio of a Bloch frequency to a laser frequency, represented as $\eta $, equals unity. In the actual calculations based on the Rmatrix Floquet theory, it is revealed that, in a largeF$_{\mathrm{ac}}$region, EDOS for $\eta =$ 1 shows a complicated spectral structure composed of a couple of newly growing peaks, in contrast to EDOS for $\eta =$ 3 which just shows a monotonic change of a single spectral peak. It is speculated that the pronounced feature of the former spectra is attributed to the Fanolike multichannel resonance mechanism, whereas the feature of the latter case is attributed to the multichannel nonresonance mechanism. [1] Y. Nemoto, K. Hino, and N. Maeshima, Phys. Rev. B 87, 205305 (2013). [Preview Abstract] 

C1.00160: Collapse of Fractal Structure in a Dynamic Fractional Stark Ladder Driven by an Intense THz Laser Kenichi Hino, Fumitaka Ohno, Yuya Nemoto, Nobuya Maeshima We examine a dynamic WannierStark ladder in biased semiconductor superlattices driven by a monochromatic THz laser with a fractional matching ratio $\eta $; this is the ratio of a Bloch frequency$_{\mathrm{\thinspace }}$to a laser frequency. This type of a dynamic WanneirStark ladder is termed a dynamic fractional Stark ladder (DFSL). It is known that a DFSL shows fractal structure in quasienergy levels as a function of 1/$\eta $ based on a tightbinding model [1]. However, with the increase in intensity of an irradiated laser, it is found that photonassisted tunneling causes singlechannel shaperesonance with quasienergy shift and width, making inaccurate the abovementioned fractal structure [2]; the channel means a photon sideband of DFSL. In present study, we investigate the resonance structure of DFSL involving stronger interchannel interactions relevant to acZener tunneling by applying a multichannel scattering based on the Rmatrix Floquet theory. The obtained results show that conspicuous redshift of resonance spectral peaks and the associated resonance decay, concluding the collapse of the fractal structure characteristic of DFSL. [1]X. G. Zhao, et al., Phys. Lett. A 202, 297 (1995). [2]T. Karasawa, et al., Solid State Comm 151, 392 (2011). [Preview Abstract] 

C1.00161: Semiclassical Theory of Coherent Phonon Generation Accompanying Transient Fano Resonance in Semiconductors Yohei Watanabe, Yuya Nemoto, Kenichi Hino, Nobuya Maeshima The recent advancement of ultrashortpulse laser technology and timeresolved spectroscopy techniques have made it possible to observe coherent phonon generation. In particular, in $n$type Si, transient Fano resonance was observed experimentally in the initial stage of coherent phonon generation, and it was speculated that this phenomenon results from the manifestation of polaronic quasiparticles composed of electrons and phonons which interact strongly each other [1]. In this study, we are aimed at constructing a semiclassical picture of the coherent phonon generation by virtue of Dyson's bosonization method which makes it possible to give form to the abovementioned speculation. In the present picture, we can incorporate a variety of quantum effects on an equal footing, where the effects are such as the transient Fano resonance and further the effects of both intraband and interband transitions relevant to pair excitation of electrons, plasmon, exciton, bandgap renormalization, and so on. In addition, we make a comparison of the present model with the classical model recently reported [2]. [1] M. Hase, et al., Nature 426, 51 (2003) [2] D. M. Riffe, Phys. Rev. B 84, 064308 (2011). [Preview Abstract] 

C1.00162: A reparametrization approach of the B3LYP functional based on the equilibrium temperature of the spin crossover Ahmed Slimani, Xuefang Yu, Azusa Muraoka, Kamel Boukheddaden, Koichi Yamashita The theoretical study of the electronic structure of spin crossover compounds is very challenging due to the technical limitations of highly accurate abinitio methods and/or the inaccuracies of density functional methods in the prediction of low spin/highspin energy splitting. However, calculations using the reparametrized functionals could improve the results. We present an investigation of the HS/LS energy gap of a typical spin crossover compound using several DFT functionals. We propose a reparametrization approach based on the equilibrium temperature of the spin crossover compounds leading to reasonable estimation of the HS/LS energy gap. In fact, the proposed approach is very important to match the used functional to the considered spin crossover compound. [Preview Abstract] 

C1.00163: Terahertz study of mplane GaN thin fims Shaham Quadir, DerJun Jang, ChingLiang Lin, Ikai Lo We investigate the optical properties of mplane GaN thin films using the terahertz time domain spectroscopy. The mplane GaN thin films were grown on $\gamma $LiAlO$_{2}$ substrates with buffer layers of low temperature grown GaN. The thin films were illuminated with terahertz radiation generated by a LTGaAs antenna and the transmitted signal was detected by a ZnTe crystal. The polarization of the terahertz wave was chosen to be either parallel or perpendicular to the GaN [0001] direction. We compared the transmitted signals of the mplane GaN thin films to that of the LAO substrate. The samples as well as the LAO substrate exhibited polarization dependence of absorption in terahertz spectrum. The carrier densities and the mobilities were derived from the transmittance of the THz wave using extended Drude model. We found, in all samples, both the carrier densities and mobilities along the GaN [0001] direction were smaller than those along the GaN [11\underline {2}0] direction due to the stripe formation along the GaN [11\underline {2}0]. [Preview Abstract] 

C1.00164: Nonradiative recombination in InN thin films JianYu Chen, DerJun Jang, Shaham Quadir, LiWei Tu InN thin films grown by molecular beam epitaxy were investigated by timeresolved photoluminescence (TRPL) upconversion apparatus. The samples were illuminated by laser pulses from a Ti:sapphire laser with the energy of 1.5 eV and the pulsewidth of 100 fs. The intensity of the TRPL decays rapidly as the temperature and pumping inentensity increase. The radiative and nonradiative decay rates as a function of carrier density were derived from the TRPL signals at various temperatures. The ShockleyReadHall, radiative recombination, and Auger recombination coefficients were obtained by fitting the derived decay rates with the rate equation. The radiative decay times determined from the rate equation is comparable to theoretical prediction. The SRH coefficient is proportional to the background carrier density. In all samples, we found the Auger rates increase with the temperature and carrier density. The phononassisted Auger recombination was found to be the dominant process in the nonradiative recombination. [Preview Abstract] 

C1.00165: Atomistic Simulation of Electronic and Optical Properties of (100), (110) and (111) Oriented InAs/GaAs Quantum Dots Vinay Chimalgi, Shaikh Ahmed Recent advances in growth techniques and increasing number of experimental studies have made semiconducting InAs/GaAs quantum dots (QDs) grown along different crystallographic directions a reality and promising systems for applications in infrared detection, optical memories, laser, and in quantum cryptography as single photon sources and quantum computation. However, only few theoretical investigations have been performed on these QDs due to the complex nature of the coupling of atomicity, structural fields, polarization, and quantum sizequantization, all strong function of the crystallographic direction. The objective of this paper is to integrate a computational framework employing a combination of fully atomistic valence forcefield molecular mechanics and 20band \textit{sp}$^{3}s*d^{5}$SO tightbinding based electronic bandstructure models, and numerically investigate the effects of internal fields on the electronic and optical properties of InAs/GaAs quantum dots grown on (100), (110), and (111) orientated substrates. It is found that, while piezoelectricity has largest effects on lowering the symmetry of (100) oriented QDs, its effect is minimum in (111) orientated QDs. [Preview Abstract] 

C1.00166: Timeresolved photoluminescence study of mplane GaN thin films JiHong Pan, DerJun Jang, Shaham Quadir, Ikai Lo The optical properties and the carrier relaxation of GaN thin films were studied by timeresolved photoluminescence apparatus. The mplane GaN thin films were grown on GaN buffer layer and $\gamma $LiAlO$_{2}$ substrates by molecular beam epitaxy with variation of N/Ga ratio. We found that the PL associated with defect is prominent for large N/Ga ratio due to the increasing of stacking faults. The intensity of PL perpendicular to the GaN [0001] direction is more intensive than that of PL parallel to the perpendicular to the GaN [0001] direction. The PL decay times exhibit dependence on the direction of the PL polarizations. [Preview Abstract] 

C1.00167: Monte Carlo study of anisotropic quantum Hall liquid phases Orion Ciftja, LeDarion Escamilla, Giancarlo Paredes, Myegan Griffin Studies of novel unconventional correlated quantum phases of electrons are a topic of great interest in condensed matter physics. In this work we provide a microscopic understanding of quantum Hall anisotropic states from the perspective of an anisotropic liquid crystalline phase with broken rotational symmetry. Even though a standard charge density wave theory serves as a good starting point to explain anisotropic behavior in quantum Hall systems, another plausible mechanism leads to less conventional phases. These quantum phases can be characterized as anisotropic electronic phases with liquid crystalline order. In this work, we present finitesize Monte Carlo simulation results that support this view for the case of anisotropic quantum Hall liquid states observed at certain quantum Hall filling factors. [Preview Abstract] 

C1.00168: Study of the TemperatureDependence of Exciton Lifetime in SingleLayer WSe$_{2}$ Xiaoxiao Zhang, Yumeng You, Fan Zhang, James Hone, Tony Heinz Twodimensional layered transition metal dichalcogenides (TMD) have recently received much attention because of their distinctive optical properties, including their strong excitonic interactions and the tightly bound trion states that they support. In this paper, we report the results of timeresolved photoluminescence measurements on exfoliated monolayer samples of WSe$_{2}$. The lifetime and quantum efficiencies of different emission features, including those from neutral and charged excitons, were found to display a strong temperature dependence over the range of 10300K. We discuss the results in terms of the structure of the conduction band near the Kpoint and of the possible roles of different exciton states. [Preview Abstract] 

C1.00169: ABSTRACT WITHDRAWN 

C1.00170: INSULATORS AND DIELECTRICS 

C1.00171: Firstprinciples study of atomic structures and electronic properties of Bi ultrathin films on Ge(111) ChiaHsiu Hsu, HuaRong Chang, FengChuan Chuang, YuTzu Liu, ZhiQuan Huang, Hsin Lin, Vidvuds Ozolins, Arun Bansil The atomic and electronic structures of ultrathin bismuth films on Ge(111) surface were investigated using firstprinciples calculations at Bi coverages ranging from 1/3 ML to 5 ML. Morphology of the surfaces varied as the coverage of Bi was increased. We found that the first layer of bismuth atoms follows the wellknown trimer model exhibiting large Rashba spinsplittings. At 2 ML, bismuth atoms of the second monolayer form the second stacking layer of trimers, whereas at 3 ML and 5 ML, bismuth atoms of the topmost two monolayers form a buckled honeycomb structure. While the electronic structures of the two topmost layers exhibit twodimensional nontrivial topological insulating phase, the bismuth atoms lying under these layers play an important role in ptype doping of the system. [Preview Abstract] 

C1.00172: Stability of Z$_2$ topological order in the presence of vacancyinduced impurity band ChungYu Mou, ShiTing Lee, ShinMing Huang Although topological insulators (TIs) are known to be robust against nonmagnetic perturbations and exhibit edge or surface states as their distinct feature, experimentally it is known that vacancies often occur in these materials and impose strong perturbations. Here we investigate effects of vacancies on the stability of Z$_{2}$ topological order using the KaneMele (KM) model as a prototype of topological insulator. It is shown that even though a vacancy is not classified as a topological defect in KM model, it generally induces a pair of degenerate midgap states only in the TI phase. We show that these midgap states results from edge states that fit into vacancies and are characterized by the same Z$_{2}$ topological order. Furthermore, in the presence of many vacancies, an impurity band that is degenerate with edge states in energy is induced and mixes directly with edge states. However, the Z$_{2}$ topological order persists and edge states exist between the impurity band and perturbed bulk bands until a phase transition occurs when Dirac cones near Dirac points are depleted. Our analyses indicate that the same scenario holds for point vacancies or line of vacancies in 3D TIs as well. [Preview Abstract] 

C1.00173: A comparative study of topological electronic structures of bilayers of group IV and V atoms ZhiQuan Huang, YuTzu Liu, ChiaHsiu Hsu, FengChuan Chuang, Hsin Lin, ChiaYu Chen, WanSheng Su, Arun Bansil The topological electronic structures of freestanding bilayers of groupIV (C, Si, Ge, Sn, and, Pb) and V (As, Sb, and, Bi) atoms under isotropic strain have been studied using firstprinciples calculations. For group IV elements, heavier elements with larger spinorbit coupling possess larger gaps at K, but a lower conduction band at $\Gamma $, making the system metallic. Only a few groupIV bilayers remain insulating due to small gaps at $\Gamma $. In contrast, for group V elements, spinorbit coupling changes the ordering of bands at $\Gamma $. While As and Sb bilayers are found to be topologically trivial without isotropic strain, strength of spinorbit coupling in Bi bilayer is large enough to induce band inversions, making the system a topological insulator. Sb bilayer also goes into a topological insulating phase if the spinorbit coupling is artificially enhanced. [Preview Abstract] 

C1.00174: Screening and atomicscale engineering of the potential at a topological insulator surface Peter Loeptien, Lihui Zhou, Jens Wiebe, Alexander Ako Khajetoorians, Jianli Mi, Bo Brummerstedt Iversen, Philip Hofmann, Roland Wiesendanger The electrostatic behavior of the prototypical threedimensional topological insulator Bi$_2$Se$_3$(111) is investigated by a scanning tunneling microscopy (STM) study of the distribution of Rb atoms adsorbed on the surface. The positively charged ions are screened by both free electrons residing in the topological surface state as well as in the quantum well states induced by band bending of the conduction band, leading to a surprisingly short screening length and small dielectric constant. Combining a theoretical description of the potential energy with STMbased atom manipulation, we demonstrate the ability to create tailored potential landscapes for the Dirac electrons with atomicscale control. [Preview Abstract] 

C1.00175: Ultrafast Dynamics of Dirac Fermions in Topological Insulator Bi2Se3 using Midinfrared pump and Terahertz probe spectroscopy Liang Luo, Tianqi Li, Xinyu Liu, Jacek Furdyna, Jigang Wang Topological insulators (TIs) represent a new state of quantum matter, which attracts a lot of recent attentions due in part to the protected Dirac cone conducting state on its surface. One key current issue is to understand the high frequency electrodynamics and charge transfer mechanism of the Dirac state and the spatially separated bulk insulating state. Here we present our investigation of these issues using femtosecond midinfrared (MIR) pump and Terahertz (THz) probe spectroscopy. Distinctly different dynamics of THz conductivity are observed with pumping below and above the bulk bandgap which allows to separate between bulk and surface contributions. The demonstrated approach provides a versatile and powerful spectroscopic tool to investigate the intrinsic Dirac fermion physics in 3D TIs.. [Preview Abstract] 

C1.00176: Growth and Characterization of Bi$_{2}$Te$_{3}$/Bi$_{2}$Se$_{3}$ Bilayers Rachel Henderson, Sercan Babakiray, Trent Johnson, Pavel Borisov, David Lederman Bi$_{2}$Te$_{3}$/Bi$_{2}$Se$_{3}$ bilayers were grown on Al$_{2}$O$_{3}$ (0001) substrates using molecular beam epitaxy. Bi$_{2}$Te$_{3}$ was grown at a stoichiometric ratio (Te/Bi) of 3:2 and Bi$_{2}$Se$_{3}$ was grown at stoichiometric ratio (Se/Bi) of 15:1. Reflection high energy electron diffraction and xray diffraction were used to confirm the epitaxial growth of these films. Xray reflectivity was used to determine the thickness and roughness of these bilayers. The magnetotransport of these heterostructures was used to determine whether charge compensation can be achieved within the bulk of the material in order to enhance the properties of surface topological states. This work was supported by a Research Challenge Grant from the West Virginia Higher Education Policy Commission (HEPC.dsr.12.29) and the West Virginia University Shared Research Facilities. [Preview Abstract] 

C1.00177: Characterization of high purity Silicon derived from Rice husk through improved Leaching process Gbadebo Yusuf, Ayodeji Awodugba, Adepoju Raimi, Babatunde Babatola Rice husk is an abundant source of silicon and silicon compounds. High purity Silicon are required in high technology products such as semiconductors and solar cell. In this work, the possibility of obtaining pure silicon compounds through leaching process was investigated. Mesoporous silica nanoparticles with amorphous morphology have been synthesized from rice husk which was further subjected to improved leaching process to obtain pure silicon. XRD analysis shows the crystal structure of the asreceived RHA with major reflections or peaks of crystalline quartz from ICSD powder diffraction occur at Bragg 2$\theta $ angles of 20.856$^{\circ}$, 26.636$^{\circ}$ and 36.541$^{\circ}$. The purity of silicon obtained in terms of silica content was improved by leaching in 10 wt{\%} hydrochloric acid. Advance future works on characterizing the electrical properties of the refined Rice Husk will eventually add value to the Rice Husk Silicon product and make it more attractive not only to the Photovoltaic industry but also other industries that require high purity silicon at reasonable cost. [Preview Abstract] 

C1.00178: Xray diffraction Microscopy of Bi2Se3 thin film on graphene/SiC Nouamane Laanait, Zhan Zhang, Paul Fenter We present an xray diffraction microscopy study of a thin film of Bi$_{2}$Se$_{3}$ on epitaxial graphene/6HSiC(001). The Bi$_{2}$Se$_{3}$ thin film, consisting of 30 quintuple layers (SeBiSeBiSe), is a topological insulator that was grown by molecular beam epitaxy. The xray microscope resolves the lateral distribution of the film thickness at the sub100 nm scale with the contrast produced by the thin film diffraction signal. Utilizing the depth penetration of xrays, we imaged the buried interfaces in this system, to probe the correlation between the structure and topography of the supporting interfaces and the growth of the thin film. We find that the Bi$_{2}$Se$_{3}$ thickness distribution closely follows the underlying substrate topography and is strongly affected by the inhomogeneous distribution of graphene near the steps of SiC, whereby nucleation induces the growth of a large number of carbon layers. Highresolution surface diffraction was also measured from this system to extract the atomic positions in the thin film to investigate the transition from graphene to Bi$_{2}$Se$_{3}$. [Preview Abstract] 

C1.00179: Synthesis and Characterization of EuPtIn$_{4}$ single crystals Priscila Rosa, Ted Grant, Camilo Jesus, Mario Piva, Pascoal Pagliuso, Zachary Fisk Rare earthbased indides present a large variety of interesting phenomena ranging from magnetism to valence fluctuation and heavy fermion superconductivity. Here we report on the synthesis and characterization of EuPtIn$_{4}$ single crystals grown by Influx. This compound adopts the orthorhombic YNiAl$_{4}$type structure (space group Cmcm) with refined lattice parameters a= 4.5424(8) \AA, b= 16.954(3) \AA, c= 7.389(1) \AA. Electrical resistivity measurements reveal a metallic behavior at high temperatures with $\rho_{\mathrm{300}\,K} = 0.02(1)$ m$\Omega$cm and a clear peak at $13.3$ K. Magnetic susceptibility measurements show CurieWeiss behaviour above 20 K followed by an antiferromagnetic phase transition at $T_{N} = 13.3$ K. The experimental magnetic moment $\mu_{\mathrm{exp}}= 7.91(5)$ $\mu_{B}$/Eu is in excellent agreement with that of the free Eu$^{+2}$ ion $\mu_{\mathrm{eff}}= 7.94$ $\mu_{B}$. Electron spin resonance measurements will shed light on the Eu$^{+2}$ spin dynamics in this compound. [Preview Abstract] 

C1.00180: Oxygen Interstitial Defects in Sc2O3 Thin Films Deposited with Reactive Ion Beam Sputtering Drew Schiltz, Peter Langston, Erik Krous, Dinesh Patel, Ashot Markosyan, Rodger Route, Carmen Menoni Numerous defects may develop when depositing amorphous thin films with reactive ion beam sputtering, including interstitials and vacancies. In many cases, these defects limit the functionality of the film, degrading both the mechanical and optical properties. This study aims to investigate the nature of oxygen interstitial point defects in scandium oxide thin films and characterize the effect on composition, optical absorption and mechanical stress. The films are deposited with argon ion beam sputtering of a scandium metal target. The density of defects is correlated with the oxygen partial pressure, revealing an optimal condition where defects are minimized. Furthermore, the defect density also demonstrates a direct correlation with the main ion beam accelerating voltage. The native oxygen defects behave as shallow levels, with binding energies in the 12 eV range. Work supported by the DoD Office of Naval Research and the High Energy Laser Program of the DoD Joint Technology Office. [Preview Abstract] 

C1.00181: Straincoupled octahedral tilts and local polar displacements in superlattices Joseph Schick, Lai Jiang, Diomedes SaldanaGreco, Andrew Rappe The ability to manipulate octahedral tilts and (anti)ferroelectric polar displacements in perovksites is a path that opens the possibility of creating new materials with desirable optical, electric, and magnetic properties. We present a density functional investigation of the ability to control tilts and displacements in various shortperiod superlattices composed of absent$A$site perovskites WO$_3$ and ReO$_3$. We demonstrate that rotations and displacements of the $B$cations in WO$_3$ are altered when layered with ReO$_3$. We also determine the thermodynamic stability of the superlattices, showing that ReO$_3$ fraction $> 50\%$ and with at least three ReO$_3$ layers are stable. [Preview Abstract] 

C1.00182: Application of Learning Methods to Local Electric Field Distributions in Defected Dielectric Materials Kim Ferris, Dumont Jones Local electric fields reflect the structural and dielectric fluctuations in a semiconductor, and affect the material performance both for electron transport and carrier lifetime properties. In this paper, we use the LOCALF methodology with periodic boundary conditions to examine the local electric field distributions and its perturbations for IIVI (CdTe, Cd(1x)Zn(x)Te) semiconductors, containing Te inclusions and small fluctuations in the local dielectric susceptibility. With inclusion of the inducedfield term, the electric field distribution shows enhancements and diminishments compared to the macroscopic applied field, reflecting the microstructure characteristics of the dielectric. Learning methods are applied to these distributions to assess the spatial extent of the perturbation, and determine an electric field defined defect size as compared to its physical dimension. Critical concentrations of defects are assessed in terms of defect formation energies. [Preview Abstract] 

C1.00183: Raman Studies of Doped Bi2Te3 and Bi2Se3 Nanosheets Courtney Keiser, Zhipeng Ye, Conor Delaney, Chee Huei Lee, Sukrit Sucharitakul, Xuan Gao, Rui He Bi2Te3 and Bi2Se3 are two representative topological insulator (TI) materials. Doping is an important way to control the bulk carrier density and surface properties of these materials. We study surface modified and doped Bi2Te3 and Bi2Se3 nanostructures by Raman spectroscopy. In Sb doped Bi2Se3 nanosheets, we found that a phase transformation in the host Bi2Se3 lattice occurs when the doping level x approaches 0.18. This is revealed by the emergence of SbSb and SbSe bond vibrations in the Raman spectra. The phase transformation is consistent with a metalinsulator transition at x~0.20 revealed in the temperature dependent electrical transport measurement. Raman characterization of Bi2Te3 nanoplates with sulfur surface passivation will also be discussed. [Preview Abstract] 

C1.00184: ME$\mu $SR study of MgO: Search for O$^{1}$ Earthquakelike Precursors G. Welch, S.B. Lee, C.E. Johnson, A. Love, C. Boekema, F.T. Freund While many precursory signals of earthquakes are known to exist, interpretation of these signals is inadequately understood [13]. Earthquakelike precursor effects are detected by studying the signals generated by positive holes in MgO using MuonSpin Resonance ($\mu $SR) and Maximum Entropy (ME). As an abundant earthcrust compound, MgO is an ideal model for studying eartquakelike signals [3]. Positive hole formation results from a break in an oxygen anion pair under elevated temperature, or high stress conditions [2]. For a 3NMgO single crystal at elevated temperatures, a small percentage of oxygen is predicted to be in an O$^{1}$ state instead of normal O$^{2}$ ions. Preliminary ME analysis of transverse field (100 Oe) $\mu $SR MgO data show asymmetrical ME peaks at $\sim$ 1.4 MHz. Small Tdependent deviations from a Lorentzian (Lor) signal seem to be effects of O$^{1}$ states in MgO. Tentatively, we have fitted ME transforms with three Lor's to obtain a reasonable description of the 1.4MHz peak. The T dependences of this 3Lor set are reported and discussed. Research is supported by RSCASJSU, SETI, WiSE@SJSU and AFC San Jose. \\[4pt] [1] FT Freund, Nat Hazards Earth Sys Sci \textbf{7} (2007) 17.\\[0pt] [2] FT Freund \textit{et al,} Phys Chem Earth \textbf{31} (2006) 389.\\[0pt] [3] K Tyson et al, SJSU internal Report (2011); S Lee \textit{et al,} abstract HUIC Educ, Math {\&} Eng Tech Conf (2013). [Preview Abstract] 

C1.00185: Proton Dynamics in the Antiferroelectric CsH$_{3}$(SeO$_{3})_{2}$ by using $^{1}$H NMR Measurements Moohee Lee, B. Ndiaye, K. Kang, H. Kim, J. Sim, Ae Ran Lim $^{1}$H NMR techniques have been employed on the antiferroelectric CsH$_{3}$(SeO$_{3})_{2}$ to measure spectrum, shift, T$_{1}$ and T$_{2}$ from 300 K down to 80 K at 4.85 T. The $^{1}$H NMR spectrum at 300 K shows a composite structure; one dominant broad peak and two small narrow peaks. From the temperature dependences of both intensity and T$_{1}$ for each peak, we identify that the narrow peaks come from rapidly moving protons whereas the broad peaks originate from rigid protons. The spectra below 200 K show several peaks associated with six nonequivalent proton sites and also the T$_{1}$ decays show a nonexponential curve coming from many proton sites. T$_{1}$ is very long even at 300 K and becomes even longer at low temperature. By analyzing T$_{1}$ decays with T$_{1S}$ and T$_{1L}$, we confirm that 1/T$_{1}$(T) show an activated behavior; the short component originates from proton dynamics with activation energy of $\sim$ 140 K and the long component is associated with that of $\sim$ 100 K. Further analysis suggests that some protons show an abrupt change in both shift and T$_{1L}$ across T$_{c}$ and may be responsible for the phase transition. [Preview Abstract] 

C1.00186: BHZ model edge states on Mobius strip Christopher Mogni, Victor Vakaryuk, Oleg Tchernyshyov We present analytical edge state solutions to the BernevigHughesZhang (BHZ) model of a quantum spin hall topological insulator with Mobius geometry. The edge state solutions are obtained by solving the differential equations governing the BHZ model. The edge states satisfy both inverted periodic boundary conditions and singlevaluedness boundary conditions. Furthermore, we develop a classification of boundary conditions compatible with the BHZ model insulator with Mobius geometry. We demonstrate that in the limit of large strip length that there exists a finite energy gap between the edge states. This energy gap does not exist for strips with periodic boundary conditions. [Preview Abstract] 

C1.00187: Title: Bi$_2$Se$_3$ Thin film topological insulators as a field effect transistor Leah Langer, Namrata Bansal, Nikesh Koirala, Matthew Brahlek, Seongshik Oh Topological insulators are materials with insulating bulk and conducting surfaces. Bi$_2$Se$_3$ is one such material. However, perfect Bi$_2$Se$_3$ topological insulators have yet to be realized because imperfections in thin film growth and intrinsic sevacancies lead to conduction in the bulk. This project explores the use of gating to eliminate bulk conduction. We demonstrate that back gating in an 8QL Bi$_2$Se$_3$ film results in reduced carrier density when negative gate voltage is applied. We also present a study of SiO$_2$ as a gate insulator for top gating Bi$_2$Se$_3$. [Preview Abstract] 

C1.00188: Exchange and correlation energies for gapped helical systems: Graphene and threedimensional topological insulators Andrii Iurov, Godfrey Gumbs, Danhong Huang A formalism is presented for calculating the exchange and correlation energies of gapped graphene as well as threedimensional topological insulators(3D TI's). With our theory, we investigate the conditions which are required to achieve entangled states of electrons in graphene and 3D TI's. These calculations are performed within the randomphase approximation (RPA). We obtain the dynamical polarization function for imaginary frequencies, which is determined by both the valence and conduction energy bands in conjunction with the overlap of the spin wave functions. We compare and specify both the differences and similarities between graphene and effective surface states in 3D TIs. The application of our derived results to quantum computation will also be explored. [Preview Abstract] 

C1.00189: Evolution of the surface states at the phase transitions between Weyl semimetal and topological insulator phases Ryo Okugawa, Shuichi Murakami Weyl semimetal phases are known to arise between topological insulator and normal insulator phases when the inversion symmetry is broken. We study changes of surface at the phase transition between Weyl semimetal and topological phases, when the system is inversionasymmetric. To this end we use the FuKaneMele model, and we add an alternating onsite potential to break the inversion symmetry. This model shows Weyl semimetal and topological insulator phases. At the phase transition, Dirac points in the bulk are created in pairs. Correspondingly we observe evolution of the surface states from the Dirac cones in the topological insulator to Fermi arc, which is a topologically protected surface in Weyl semimetals. The penetration depth of the Weyl semimetal and topological insulator is also calculated, which accounts for a gap due to finitesize effects. [Preview Abstract] 

C1.00190: Topological insulator properties of Bi$_{2}$Se$_{3}$ thin films grown by HPCVD Raj Kumar, Joseph E. Brom, Joan M. Redwing, Jingying Wang, Daniel Dougherty, Frank Hunte Topological insulators (TIs) have a bulk band gap with conducting topological surface states (TSS) where conduction through these states is protected from impurity scattering by spinmomentum locking. Bi$_{2}$Se$_{3}$ thin films typically have a high ntype carrier concentration and show metallic behavior due to native defects such as Se vacancies. This makes it very difficult to directly observe the transport properties of the TSS in highly ndoped Bi$_{2}$Se$_{3}$ TI. We deposited Bi$_{2}$Se$_{3}$ thin films on (0001) Al$_{2}$O$_{3}$ by a hybrid physical chemical vapor deposition (HPCVD) technique which uses a high Se vapor pressure to reduce Se vacancies in the film. Magnetotransport measurements on these Bi$_{2}$Se$_{3}$ films showed metallic characteristics with ntype carriers and low carrier concentration. We clearly observed topological surface states in angle resolved photoemission spectroscopy (ARPES). The results of the characterization of these films by ARPES, XRD, XPS, AFM and magnetotransport are reported and discussed in the context of surface conductivity correlated with microstructure of Bi$_{2}$Se$_{3}$. [Preview Abstract] 

C1.00191: Magnetotransport study of the ternary topological insulator (Bi$_{0.5}$Sb$_{0.5})_{2}$Te$_{3}$ via \textit{in situ} low temperature deposition of Cr Liuqi Yu, Jorge Barreda, Longqian Hu, P. Xiong, Tong Guan, Xiaoyue He, K. Wu, Y. Li The robustness of the surface state of three dimensional topological insulators against local magnetic perturbation is still under debate, since a precise and wellcontrolled electrical characterization of the effects of the ferromagnetic dopant and their evolution with doping density are exceedingly difficult. Here we report results of magnetotransport measurements on epitaxial thin films of the (Bi$_{0.5}$Sb$_{0.5})_{2}$Te$_{3}$ in the presence of electrostatic gating and magnetic impurity. Magnetoresistance (MR) and Hall effect measurements have been performed in various back gate voltages. Ambipolar field effect has been observed, enabling effective tuning of the Fermi level across the band gap and identification of the surface transport in the topological transport regime. Taking advantage of the unique capability of \textit{in situ} deposition of Cr atoms in a customized dilution refrigerator, magnetic impurities were incrementally quenchcondensed onto the sample surface. Our results show the deposition of Cr effectively yields electron doping. The weak antilocalization (WAL) effect was found to be surprisingly insensitive to the magnetic impurity; the cusplike negative magnetoconductivity remains even at the highest Cr concentration and no apparent weak localization was observed as expected from a gap opening at the Dirac point. WAL effect has the largest modification at a back gate voltage of 200 V where the Fermi level is considered relatively close to the Dirac point. [Preview Abstract] 

C1.00192: Detection of singular robust roomtemperature spin response from disordered topological Dirac fermions Lukas Zhao, Haiming Deng, Inna Korzhovska, Zhiyi Chen, Vadim Oganesyan, Lia KrusinElbaum In real threedimensional (3D) topological insulators, the Dirac fermions intermix with the typically conducting bulk thereby complicating access to the low energy (Dirac point) charge transport or magnetic response. Here we use low frequency \textit{ac } susceptibility measurements to probe spin response in the 3D topological material family: Bi$_2$Se$_3$, Bi$_2$Te$_3$, and Sb$_2$Te$_3$. We detect a remarkable paramagnetic singularity in the magnetic susceptibility at low magnetic fields which persists up to room temperature, and which we demonstrate to arise from samples' surfaces. The singularity is universal, largely independent of the bulk carrier density, and is consistent with the existence of electronic states near the spindegenerate Dirac point of the 2D helical metal. We will discuss the exceptional thermal stability of the signal; it points to an intrinsic surface cooling process of thermoelectric origin, where the rectifying configuration required for surface cooling by the the bulk is witnessed by 2$^{nd}$ harmonic generation in the subsurface region. The cooling mechanism and the singular response will be discussed within a simple Dirac model with Rashbatype spin orbit coupling. [Preview Abstract] 

C1.00193: Spectral Evolution of Raman Scattering in Sputtered Topological Insulator Films Jeff Secor, Simone Raoux, Inna Korzhovska, Lia KrusinElbaum Raman spectra of sputtered 3D topological insulator films of Bi$_{\mathrm{2}}$Te$_{\mathrm{3\thinspace }}$and Sb$_{\mathrm{2}}$Te$_{\mathrm{3}}$ were measured as a function of annealing temperature. We find that the as grown films which initially show amorphous Raman spectra develop strong and sharp Raman spectral features for annealing temperatures up to 300 degrees Celsius indicating a crystallization of the films. We show the similarities in the phonon energies between single crystal material and MBE grown films, however the phonon spectra remain less sharply defined for the polycrystalline films. Comparisons are made between thickness and film capping layers for the different topological insulators. Xray measurements and transport data also confirm that these sputtered films show crystalline properties after annealing and so sputtering can be a scalable and rapid growth method for topological electronics. [Preview Abstract] 

C1.00194: Magnetoresistance of thin film devices fabricated from bulk crystal of Bi2Se3 and Bi2Te3 Ryuta Yagi, Ryoji Sakakibara, Fumiya Tahara, Jumpei Onishi, Daishi Takegawa We have studied magnetoresistance of thin flake devices of threedimensional topological insulator, Bi$_2$Se$_3$ and Bi$_2$Te$_3$. The thin flakes were obtained by exfoliating bulk crystal mechanically, and those with thickness between 6 and 60nm were studied. We found that the behavior of the lowfield magnetoresistance measured at the low temperature, could be classified into two types in terms of weak antilocalization. The class of devices showing the quantum correction was analyzed with a standard HikamiLarkinNagaoka formalism. A best fit was obtained at a fitting parameter $\alpha$ significantly smaller than 0.5, which could be interpreted by an interaction effect between surface Dirac electrons and those in the bulk band. On the other hand, the other class of devices did not exhibit any sign of the antilocalization but exhibited parabolic magnetoresistance, although the thickness is within the same range. This is possibly due to lack of Dirac surface states because of stacking fault in the layer structure. [Preview Abstract] 

C1.00195: Imaging and manipulating mesoscopic magnetic structures in a Crdoped topological insulator (Bi,Sb)$_{2}$Te$_{3}$ Yihua Wang, John Kirtley, Xiao Feng, Ke He, Yayu Wang, Qikun Xue, Kathryn Moler The surface of a threedimensional topological insulator hosts spinpolarized metallic states which are protected by timereversal symmetry. Breaking timereversal symmetry without an external magnetic field may lead to an exotic surface quantum Hall state that supports chiral edge currents at the domain boundaries. Using scanning superconducting quantum interference device microscopy, we have imaged the magnetic structure of a 5 nmthick topological insulator BiSbTe doped with Cr. We found micronscale domains of magnetization that vanished at 15K and ferromagnetic dipoles that persisted to higher temperatures. Applying local magnetic field through a microscopic current loop, we generated switchable magnetic structures shaped like dots, stripes and patches. The ability to create, to image and to manipulate mesoscopic magnetic domain boundaries in topological insulators is an important step towards generating exotic edge states and building spinbased electronic devices. [Preview Abstract] 

C1.00196: Enhancement of dielectric constant at percolation threshold in CaCu3Ti4O12 ceramic fabricated by both solid state and solgel process Rupam Mukherjee, Lucia Garcia, Gavin Lawes, Boris Nadgorny We have investigated the large dielectric enhancement at the percolation threshold by introducing metallic RuO$_{2}$ grains into a matrix of CaCu$_{3}$Ti$_{4}$O$_{12}$ (CCTO). The intrinsic response of the pure CCTO samples prepared by solid state and solgel processes results in a dielectric constant on the order of 10$^{4}$ and 10$^{3}$ respectively with low loss. Scanning electron microscopy and energy dispersive xray spectroscopy indicate that a difference in the thickness of the copper oxide enriched grain boundary is the main reason for the different dielectric properties between these two samples. Introducing RuO$_{2}$ metallic fillers in these CCTO samples yields a sharp increase of the dielectric constant at percolation threshold f$_{\mathrm{c}}$, by a factor of 6 and 3 respectively. The temperature dependence of the dielectric constant shows that the dipolar relaxation plays an important role in enhancing dielectric constant in composite systems. [Preview Abstract] 

C1.00197: ATOMIC, MOLECTULAR AND OPTICAL PHYSICS 

C1.00198: A method of identifying higher order quantum accelerator modes in the quantumdeltakicked rotor Vijayashankar Ramareddy, Gil Summy Quantum accelerator modes (QAM) are signatures of resonances in the quantum evolution of the deltakicked accelerator. Experimentally this system is realized by exposing a BoseEinstein condensate to short ``kicks'' from an optical standing wave. This atom optical implementation of the kicked accelerator shows that the QAM consists of momentum states that rephase during the free evolution between the kicks. We show that higher order modes rephase after few kicks. We present a method of identifying the higher order QAMs using the rephasing model and show that the momentum state step structure of these modes directly correlates with that predicted by the rephasing model. We also show that the step structure is replaced by a sinusoidal behavior for the momentum states in quantum kicked rotor due to the presence of antiresonance which occurs for phase evolution of odd multiple of $\pi$. The step size can be used to classify the higher order modes [1].\\[4pt] [1] Vijayashankar Ramareddy and Gil S Summy, ``Detailed momentum structure of the higher order quantum accelerator modes'' in preparation [Preview Abstract] 

C1.00199: Matrix Effects on Boron Containing Materials due to Laser Ablation Molecular Isotopic Spectrometry (LAMIS) Staci R. Brown, Charlemagne A. Akpovo, Jorge Martinez, Alan Ford, Kenley Herbert, Lewis Johnson Laser Induced Breakdown Spectroscopy (LIBS) is a spectroscopic technique that is used for the qualitative and quantitative analysis of materials in the liquid, solid, or gas phase. LIBS can also be used for the detection of isotopic shifts in atomic and diatomic species via LaserAblation Molecular Isotopic Spectroscopy (LAMIS). However, any additional elements that are entrained into the plasma other than the element of interest, can affect the extent of ablation and quality of spectra and hence, potentially obscure or aid in the relative abundance assessment for a given element. To address the importance of matrix effects, the isotopic analysis of boron obtained from boron oxide (BO) emission originating from different boroncontaining compounds, such as boron nitride (BN), boric acid (H$_{3}$BO$_{3})$, and borax (Na$_{2}$B$_{4}$O$_{7}$\textbullet 10H$_{2}$O), via LIBS has been performed here. Each of these materials has different physical properties and elemental composition in order to illustrate possible challenges for the LAMIS method. A calibrationfree model similar to that for the original LAMIS work is used to determine properties of the plasma as the matrix is changed. [Preview Abstract] 

C1.00200: Energy deposition of quasitwo temperature electrons in fast ignition scenario Seyed Abolfazl Ghasemi, Amir Hossein Farahbod Our calculations show that, by using quasi two temperature electrons energy distribution function and increasing electrons energy from 5 keV to 7 MeV, the ratio of beam Blooming to Straggling definitely decreases. Our analytical analysis show that for fuel mass \textgreater 1 mg and for $\lambda_{if} >0.53\mbox{\, }\mu m$, straggling and beam blooming increases. Meanwhile, by reducing fast ignitor wavelength from 0.53 to 0.35 micron, and for fuel mass \textgreater 2 mg, electron penetration into the dense fuel slightly decreases. It is seen that for cold fuel density $\rho _{c}=$ 292 g.cm$^{3}$, $_{\, }$as the residual electron energy increases from 5 keV to 7 MeV, the ratio of beam blooming to the mean electron penetration decreases. Therefore, reduction of scattering (blooming and straggling) of electrons and enhancement of electron penetration in the dense fuel, can be obtained in relativistic regime with high energy electrons of the order of 7 Mev and more which effectively can be used in fastshock ignition concept. [Preview Abstract] 

C1.00201: Collective Excitations of BoseÂEinstein Condensates In Isotropic and Slightly Anisotropic Traps Andrew Barentine, Dan Lobser, Heather Lewandowski, Eric Cornell Boltzmann proved that the monopole mode of a thermal gas in an isotropic, harmonic and 3D trap is undamped. BoseEinstein Condensates (BECs) are not classical gases and their weakly interacting nature causes damping in a 3D monopole mode. The large parameter space of the TOP (Timeaveraged Orbiting Potential) trap allows for precise control of the trap geometry. Exciting a monopole mode in a BEC as well as its canonical thermal cloud allows us to investigate damping effects in isotropic and slightly anisotropic traps for both hydrodynamic and collisionless regimes. We also hope to achieve a greater understanding of the frequency shifts due to anharmonicity in the trap in order to apply this to our research on quasi2D monopole modes. [Preview Abstract] 

C1.00202: Positronium Formation from positron impact off hydrogen and helium targets Eric Stacy, T.C. Naginey, B.B. Pollock, H.R. Walters, Colm T. Whelan Charge exchange cross sections are presented for collisions of positron and protons with hydrogen, neutral and singly ionized helium targets, using a variant of the classical trajectory monte carlo (CTMC) approach. The basic physics of $e^{+}$; $e^{}$ creation and annihilation is overviewed. It is shown that for atomic hydrogen and helium targets electron capture by a free positron to form Positronium is vastly more probable than inflight annihilation. Good agreement with available experiment is found and the charge cross section for positron of He+ predicted. [Preview Abstract] 

C1.00203: Tunable LatticeInduced Opacity for Matter Wave Transport Chen Zhang, Chris H. Greene We describe the novel phenomena of latticeinduced opacity in the process of matter wave scattering from a two dimensional atomic lattice. As an analogue to the confinementinduced resonance, the two dimensional atomic lattice can be tuned to complete opacity to a normally incident low energy matter wave, by changing the swave scattering length between the matter wave and the atoms in the lattice. A scheme for a matter wave transistor is proposed based on the transmissionreflection properties of the matter wave through the atomic lattice. We also propose a matter wave cavity, constructed by two parallel 2D atomic lattices that are both opaque to the matter wave. In higher kinetic energy regimes of the matter wave, the two dimensional atomic lattice is shown to be a matter wave beam splitter and wave plate, with tunable peak intensity into different directions. [Preview Abstract] 

C1.00204: Hydrodynamic theory of rotating ultracold supersolids Sankalpa Ghosh, Rashi Sachdeva Ultra cold atomic condensate with long range interaction is considered as a possible candidate to realize the supersolid phase. Such a supersolid phase can be subjected to artificial gauge field created either through rotation or by introducing space dependent coupling among hyperfine states of the atoms using Raman lasers. Starting from a GrossPitaevskii energy functional that describes such systems at zero temprature we construct hydrodynamic theory to describe the low energy long wavelength excitations of such rotating supersolid of weakly interacting ultra cold atoms for generic type of long range interaction. We treat the supersolid within the framework of well known two fluid approximation. We consider such system in the fast rotation limit where a vortex lattice in superfluid coexists with the supersolid lattice and analytically obtain the dispersion relations of collective excitations around this equilibrium state. The dispersion relation suggests a mode splitting due to the existence of two lattices which can be experimentally measured within the current technology. We point out that this can clearly identify such a ultra cold atomic supersolid phase. Ref. Rashi Sachdeva and Sankalpa Ghosh arXiv: 1308.1592 (CondMat) [Preview Abstract] 

C1.00205: Fractional Quantum Hall Effects in a TwoDimensional Atomic Gas Jianshi Zhao, Louis Jacome, Nathan Gemelke Fractional Hall effects in twodimensional electron gases have dramatically altered the way we look at ordering in quantum many body systems. Despite heroic advances since their discovery, many predictions regarding unique behavior have yet to be observed. We describe new efforts to produce similar effects in cold atomic Bose gases. Previous experiments have observed strong correlation in large ensembles of rapidly rotating few body samples consistent with a description using bosonic analogues of fractional hall states. We describe extensions of these experiments to observe individual systems in a quantum gas micropscope, introduce strong interactions through Feshbach resonance, and extend effects to larger numbers of atoms. The use of impurity atoms to probe fractional hall droplets will also be discussed, as will the extension of these effects to higher spin samples by using multiple internal states of Rubidium87. [Preview Abstract] 

C1.00206: An Experimental Extraction of Entanglement Entropy in an Ultracold Atomic Gas Craig Price, Qi Liu, Nathan Gemelke Entanglement is a widespread phenomenon present throughout much of condensed matter physics that governs the behavior of the thermodynamic ground state of many materials. Despite its dominant role in determining the character of a manybody sample, the quantification and direct experimental extraction of the degree to which a sample is entangled has presented a significant challenge. We describe methods for experimentally extracting entanglement entropy from a cold atomic sample held in an optical lattice. To do so, controlled collisions are induced between atoms in the sample and an array of auxiliary probe atoms which are followed by destructive optical detection of the probes. For a sample with significant preexisting long range entanglement, such as topologically ordered matter or quantum critical systems, quantum backaction affects the sample in regions extending beyond where probed resulting in a nonlocal thermal effect. Subsequent measurement of the local equation of state can reveal the entanglement entropy. We discuss a unique apparatus to perform these manipulations and its application to interrogating strongly correlated gases in optical lattices, including phenomena of quantum magnetism, cooling of a Mott Insulator, and nonequilibrium phenomena. [Preview Abstract] 

C1.00207: Spectroscopic measurement of impurity ions in crystals using Whispering Gallery Modes and application to hybrid qantum systems Michael Tobar, Daniel Creedon, Warrick Farr, Natalia Carvalho, Pavel Bushev, Maxim Goryachev, JeanMichel Le Floch Crystal resonators with paramagnetic ion impurities are promising devices for hybrid quantum systems. However, a tradeoff exists between cavity coherence time and ion concentration. As a result, it is important to characterize crystals with varying levels of concentration and in the experimental regime where quantum effects occur (millikelvin temperature at microwave frequencies). Here, we describe recent progress in sensitive spectroscopic measurements of paramagnetic impurity ions in crystals. Using hybrid Whispering Gallery Mode and Electron Spin Resonance techniques, interactions between photons and impurity ions in crystalline microwave cavities are studied. Rigorous spectroscopy of singlecrystal sapphire and rare earth doped YAG and YSO was performed over the frequency range 819 GHz, and external DC magnetic fields of up to 0.9 T. Measurements of a high purity sapphire reveal the presence of Fe3+, Cr3+, and V2+ impurities, with quadrupole and hyperfine structure, as well as coupling between spins and photons of up to 6MHz. Also, new transitions in Erbium doped YSO crystals are observed in the strong coupling regime and will be presented at the conference. [Preview Abstract] 

C1.00208: Towards the Detection of Momentum Entangled Atom Pairs Michael Keller, Mateusz Kotyrba, Maximilian Ebner, Anton Zeilinger We present our work towards the creation and detection of momentum entangled states of metastable helium (He*) atoms. Starting from a BoseEinstein condensate (BEC) of metastable helium, stimulated Raman transitions transfer momentum onto the atoms. Subsequent collisions between two counterpropagating matter waves lead to atom pairs that are entangled in their momentum degree of freedom. This state represents a threedimensional version of the one discussed in the EinsteinPodolskyRosen gedankenexperiment. By using a position resolved microchannel plate (MCP) detector the high internal energy of the He* atoms of almost 20 eV per atom allows for efficient detection of individual atoms with a high spatial and temporal resolution. We show that a double doubleslit as well as a ghost interference scheme can be used to show the entanglement and that those schemes are feasible with experimental restrictions in our setup. We discuss the main challenges in the experimental realization and present the present status of the experiment. [Preview Abstract] 

C1.00209: Anisotropic turbulence of a dipolar exciton BoseEinstein condensate in coupled quantum wells George Tishinski, Oleg Berman, German Kolmakov We report formation of turbulence in a nonequilibrium BoseEinstein condensate (BEC) of dipolar excitons trapped in a confining parabolic potential. This turbulent state is characterized by strong nonequilibrium oscillations of the occupation numbers for the excitons states in the presence of the energy source and exciton decay. By considering the potentials where a spring constant in one direction differs from that in another direction, we study a transition from isotropic twodimensional turbulence to anisotropic turbulence and then, to quasione dimensional turbulence. We discuss application of the theory of wave turbulence to the description of turbulent states in an exciton BEC. [Preview Abstract] 

C1.00210: Dimensional crossover and coldatom realization of gapless and semimetallic Mott insulating phases Peter P. Orth, Mathias Scheurer, Stephan Rachel We propose a realistic coldatom setup which allows for a dimensional crossover from a twodimensional quantum spin Hall insulating phase to a threedimensional strong topological insulator phase by simply tuning the hopping between the layers. We further employ cluster slaverotor meanfield theory to study the effect of additional Hubbard onsite interactions that give rise to various spin liquidlike phases such as gapless and semimetallic Mott insulating states. [Preview Abstract] 

C1.00211: Majorana zero modes in a one dimensional Fermi gas with spin orbit coupling and attractive interactions Jonathan Ruhman, Ehud Altman Majorana zero modes can emerge at the edge of a nano wire subject to Rashba like spinorbit interaction and a Zeeman field, which is coupled through a proximity effect to an swave superconductor. Can the zero modes obtain even if the superconductivity is intrinsic, due to attractive interactions in the single channel wire, with strictly conserved charge? We answer this question in the affirmative and provide an exact low energy description of the Majorana modes at the interface between a low density ``trivial'' Luttinger liquid on one side and a high density ``topological'' Luttinger liquid on the other side. The energy splitting of a pair of such modes at the edges of a topological segment of length $L$ scales as $1/L^{K/2}$ where $K>1$ is the Luttinger parameter. We discuss how to detect these Majorana modes in systems of ultra cold atoms, where an intrinsic attractive interaction is indeed much more natural than proximity induced pairing. [Preview Abstract] 

C1.00212: SuperfluidMott insulator transition of spin1 bosons in optical resonators Lu Zhou, JunNi Wu, Jing Qian, XingDong Zhao, Weiping Zhang We consider an antiferromagnetic spin1 BoseEinstein condensate confined in a FabryP\'erot optical resonator, in which the intracavity light field form an optical lattice potential for the atoms. Special emphasis is paid to the cavitymediated superfluidMott insulator transition. We found that exotic phase diagrams can appear due to the competition between cavityinduced nonlinear interaction and the atomic spindependent collision interactions. [Preview Abstract] 

C1.00213: Supersolidity of dipolar Fermi gas in a simple cubic optical lattice TianSheng Zeng, Lan Yin We study the phase diagram of a dipolar fermi gas at halffilling in a cubic optical lattice with dipole moments aligned along the $z$axis. The anisotropic dipoledipole interaction leads to the competition between $p_{z}$wave superfluid and nematic chargedensitywave (CDW) orders in the system at low temperatures. We find that the superfluid phase is favored with weak interactions, while the CDW phase dominates with strong interactions. In between, the supersolid phase appears due to the competition between superfluid and CDW orders. The superfluid densities are anisotropic in the supersolid and superfluid phases. In the CDW phase, there is a semimetal to insulator transition with the increase of the interaction strength. The implication for experiments is discussed. [Preview Abstract] 

C1.00214: Quantum dynamics with strongly interacting Rydberg atoms Jing Qian, Lu Zhou, Xingdong Zhao, Weiping Zhang Rydberg atoms with high principal quantum number have exaggerated atomic properties, including strong dipoledipole interactions, long radiative lifetimes and so on. These properties can provide intriguing routes to study attractive quantum manybody dynamics. In this talk, we present three research works with strongly interacting Rydberg atoms. We study quantum nonequilibrium phases of Rydberg atoms in cubic and triangular optical lattices and find exotic quantum phases such as uniform phase, antiferromagnetic phase, and oscillatory phase. In some parameter areas, bistability phase can be observable. Except that, in a triangle lattice, we also identify dynamical chaos effect in the stronginteraction limit. Besides, depending on the strong dipoledipole interactions between Rydberg states, Rydberg blockade effect appears. In a more recent work, we find the effective twoatomblockade spherical model can reveal anisotropic deformation and shrunken properties when the real number of atoms increases from two to three in fewtom systems. These results will all be discussed in the talk. [Preview Abstract] 

C1.00215: Polarons in a dipolar condensate Hong Ling, Ben Kain We consider a polaronic model in which impurity fermions interact with background bosons in a dipolar condensate. The polaron in this model emerges as an impurity dressed with a cloud of phonons of the dipolar condensate, which, due to the competition between the attractive and repulsive part of the dipoledipole interaction, obey an anisotropic dispersion spectrum. We study how this anisotropy affects the Cerenkov radiation of Bogolubov phonon modes, which can be directly verified by experiments in which a dipolar BEC moves against an obstacle. We study the spectral function of the impurity fermions, which is directly accessible to the momentum resolved rf spectroscopy experiments in cold atoms. This work is supported in part by the US Army Research Office under Grant No. W911NF1010096 and in part by the National Science Foundation under Grant No. PHY1125915. [Preview Abstract] 

C1.00216: Formation and detection of a chiral orbital Bose liquid in an optical lattice Xiaopeng Li, Arun Paramekanti, W. Vincent Liu, Andreas Hemmerich Recent experiments on porbital atomic bosons have suggested the emergence of a spectacular ultracold superfluid with staggered orbital currents in optical lattices. This raises fundamental questions like the effects of collective thermal fluctuations, and how to directly observe such chiral order. Here, we show via Monte Carlo simulations that thermal fluctuations destroy this superfluid in an unexpected twostep process, unveiling an intermediate normal phase with spontaneously broken timereversal symmetry, dubbed ``chiral Bose liquid.'' For integer fillings ($n\ge2$) in the chiral Mott regime, thermal fluctuations are captured by an effective orbital Ising model, and Onsager's powerful exact solution is adopted to determine the transition from this intermediate liquid to the paraorbital normal phase at high temperature. A suitable lattice quench is designed to convert the staggered angular momentum, previously thought by experts difficult to directly probe, into coherent orbital oscillations, providing a smokinggun signature of chiral order. [Preview Abstract] 

C1.00217: Density functional theory for stronglycorrelated ultracold dipolar gases Francesc Malet Giralt, Stephanie Reimann, Paola GoriGiorgi We address quasionedimensional stronglycorrelated dipolar ultracold gases by means of density functional theory. We make use of an approximation for the Hartreeexchangecorrelation that has been shown to be very accurate for electronic systems with coulombic interactions. We show that this approach allows to treat systems with very large particle numbers at relatively low computational cost. [Preview Abstract] 

C1.00218: Kinetic coefficients of the twodimensional attractive Fermi gas: beyond fermionic quasiparticles Ville Pietil\"a, Mehrtash Babadi We calculate the static and dynamic shear viscosity and spin diffusion coefficients of a twodimensional attractive Fermi gas within the Nozi\`eresSchmittRink approximation, and study their evolution from the weakcoupling Fermi liquid to the strongcoupling composite Bose liquid regime. We find that the inclusion of bosonic contributions in the transport processes is crucial in order to explain the appearance of the hydrodynamic minimum of the kinetic coefficients, as also observed in recent experiments with twodimensional ultracold Fermi gases. [Preview Abstract] 

C1.00219: Darksoliton dynamics and snake instability in superfluid Fermi gases trapped by an anisotropic harmonic potential Wen Wen We present an investigation of generation, dynamics and stability of dark solitons in anisotropic Fermi gases for a range of particle numbers and trap aspect ratios within the framework of the orderparameter equation. We calculate the periods of dark solitons oscillating in a trap, and find a good agreement with the results based on the Bogoliubovde Gennes equations. By studying the stability of initially offcenter dark solitons under various tight transverse confinements in the unitarity limit, we not only give the criterion of dynamical stability, but also find that the soliton and a hybrid of solitons and vortex rings can be characterized by different oscillation period. The stability criterion is not fulfilled by the parameters of the recent experiment of Yefsah {\it et} al.[Nature {\bf 499}, 426 (2013)]. Therefore, instead of a very slow oscillation as observed experimentally, we find that the created dark soliton undergoes a transverse snake instability with collapsing into vortex rings, which propagate in solitonlike manner with a nearly two times larger period. [Preview Abstract] 

C1.00220: Effecs of disorder on a twodimensional ultracold gas in BCSBEC crossover B. Tanatar, A. Khan We investigate the effect of static impurities in a twodimensional ultracold atomic gas as a function of twobody bound state energy. We incorporate disorder from impurities through fluctuations and study its effects on the BCSBEC crossover. The analysis on the quasihomogeneous system reveals depletion of energy gap on the BCS and BEC sides according to the usual expectation but interestingly in the intermediate region (moderate binding energy or crossover), the paring gap turns out to be same as its clean Fermi gas limit. This motivates us to study the density of states (DOS) and spectral gap, which suggest that the effect of disorder is smallest in this region. [Preview Abstract] 

C1.00221: Heat capacity ratio and sound velocities for a Bose gas in multislabs O.A. Rodriguez, M.A. Solis The heat capacity ratio ($c_p/c_V$) and adiabatic sound velocity ($c_S$) are reported for an inhomogeneous Bose gas with mass distribution arranged in multislabs. The mass distribution is generated by applying a KronigPenney potential in one direction on a 3D Bose gas while the bosons are free to move in the other two directions. Since the isobaric specific heat is indeterminate for $T \leq T_c$, we show the heat capacity ratio as a function of $T$ only for $T > T_c$, for six values of potential spatial period $a+b$: it diverges at $T_c$, after a threshold temperature we recover the 3D classical value 5/3, and for intermediate temperatures its behavior shows a dimensional ``crossover" from 3D to 2D. The average adiabatic sound velocity has two main features: above $T_c$ it is proportional to $T^{1/2}$, as a classical gas, while for temperatures below $T_c$ it goes as $T^{5/4}$ with a small deviation from this value which depends on the lattice parameter. [Preview Abstract] 

C1.00222: Cavity Quantum Electrodynamics with a Rydbergblocked Atomic Ensemble Kyle Arnold, Chern Hui Lee, Murray Barrett We report our experimental progress towards trapping of a cold ensemble with Rydbergexcited atoms in a high finesse optical cavity. Initial experiments are being performed in a moderate finesse (F$=$1200) cavity and high finesse (F$=$100,000) cavity experiment is currently under construction. This system will allow for realization of an optical nonlinearity which is both nondissipative and sufficiently strong to be useful at the single photon level. Such a system has numerous applications for quantum information, in particular, the implementation of a twophoton phase gate. [Preview Abstract] 

C1.00223: NonMarkovian Quantum Limit for Driven Open Quantum Systems Andr\'es EstradaGuerra, Leonardo A. Pach\'on The observation of quantum features at macroscopic scales, like superconductivity, interference fringes of massive manyatoms molecules [1], coherent superpositions in BoseEinstein condensates [2], and superconductivity make the border between the quantum and classical realms diffuse and intricate. It is commonly accepted that in order to observe these quantum features, one needs to reach the low temperature regime, that is, the typical energy of the system must be greater than the thermal fluctuations. Our work aims to show that, even in the high temperature regime, some quantum features such entanglement can be present if the system is placed out from equilibrium. In particular, we study the nonMarkovian dynamic of two different resonators coupled to different baths at different temperatures and with different couplingtothebathstrengths. We found that entanglement between the resonators can be created and maintained in the longtime regime, a processes that is assisted by the driving and by the nonMarkovian dynamics. We also derive a new relation between the parameters of the system leading to the survival of entanglement.\\[4pt] [1] K. Hornberger \textit{et al}., New J. Phys. \textbf{11}, 043032 (2009). \\[0pt] [2] M. R. Andrews \textit{et al.}, Science \textbf{275}, 637 (1997 [Preview Abstract] 

C1.00224: Limits on parameter sensitivity using Quantum ZivZakai bound Bhaskar Roy Bardhan, Kaushik Seshadreesan, Hwang Lee, Jonathan Dowling Quantum ZivZakai bound provides a limit on the achievable precision depending on probability distribution characterizing the prior information of a binary decision problem. We investigate the limits for parameter sensitivity in quantum estimation theory for pathentangled photon Fock states. Based on the quantum ZivZakai bound, we study some lower bounds on the sensitivity in an interferometric setup, and verify our results considering the effects of repeated and adaptive measurements. We also compare the limits with the quantum CramerRao bound for robust pathentangled Fock states for a given priority information. [Preview Abstract] 

C1.00225: Integrated superconducting photon detectors for ion trap quantum information processing D.H. Slichter, V.B. Verma, S.W. Nam, D. Leibfried, D.J. Wineland Quantum state measurement of trapped ions relies on detecting fluorescence photons from a laserdriven atomic transition. Typically, the ion fluorescence is collected by highnumericalaperture (NA) optics and detected using a camera or photomultiplier tube. However, the quantum efficiency of these detectors is below 40\% at the wavelengths of interest for many ion species (generally in the UV). Furthermore, the collection optics are bulky and have a limited field of view, making it difficult to scale this method up to simultaneous detection in multiple locations. These issues can be addressed by integrating highNA photon detectors into the ion trap structure. Superconducting nanowire singlephoton detectors (SNSPDs) have demonstrated quantum efficiencies above 90\% and have collection areas large enough to give the desired NA. SNSPDs use simple, compact bias and readout electronics and could be multiplexed to allow simultaneous independent readout from many individual trap zones. We report progress on integrating an SNSPD into a surfaceelectrode RF ion trap, including measurements of quantum efficiency and performance in the presence of RF trapping potentials. [Preview Abstract] 

C1.00226: ABSTRACT MOVED TO Q35.00014 

C1.00227: Observable most probable trajectories of quantum switching in modulated oscillator Vittorio Peano, Mark Dykman Quantum fluctuations lead to a finite width of the distribution of a modulated system over its quasienergy (Floquet) states even for zero temperature of the bath to which the system is coupled. We study the resulting distribution for a periodically modulated oscillator. Of special interest are large rare fluctuations responsible for the tail of the distribution over quasienergy and for switching between metastable states of forced vibrations. We find the most probable paths followed by the quasienergy in rare events, including switching. Along with the switching rates, such paths are observable characteristics of quantum fluctuations. As we show, they can change discontinuously once the detailed balance condition is broken. Knowledge of such paths suggests a new way of quantum control of rare events [Preview Abstract] 

C1.00228: Development of a low cost infrared spectrophotometer and a Matlab program to detect terrestrial and extraterrestrial water vapor Lakshmi Raju The objective of this project was to develop a low cost infrared spectrophotometer to measure terrestrial or extraterrestrial water vapor and to create a Matlab program to analyze the absorption data. Narrow bandwidth infrared filters of 940 nm and 1000 nm were used to differentially detect absorption due to vibrational frequency of water vapor. Light travelling through a collimating tube with varying humidity was allowed to pass through respective filters. The intensity of exiting light was measured using a silicon photodiode connected to a multimeter and a laptop with Matlab program. Absorption measured (decrease in voltage) using the 940nm filter was significantly higher with increasing humidity (p less than 0.05) demonstrating that the instrument can detect and relatively quantify water vapor. A Matlab program was written to comparatively graph absorption data. In conclusion, a novel, low cost infrared spectrophotometer was successfully created to detect water vapor and serves as a prototype to detect water on the moon. This instrument can also assist in teaching and learning spectrophotometry. [Preview Abstract] 

C1.00229: Electronic Structure Mediated Vibrational Coherence in Methyl Acetophenone Isomers Arkaprabha Konar, Yinan Shu, Benjamin Levine, Vadim Lozovoy, Marcos Dantus The role of ground and excited state electronic structures in influencing the vibrational coherences in gas phase polyatomic molecules has been a hot topic for quite some time. Here we explore the time resolved dynamics of acetophenone and its methyl substituted isomer when excited by intense 800nm femtosecond pump and probe pulses. The parent ion yield show 500 fs modulations that die down within 3ps. Similar modulations having the same timescales in the parent ion yield are also observed for the pmethyl isomer. The omethyl isomer however shows longer 1ps modulations. Interestingly enough no oscillations are observed for the meta isomer. Quantum chemical calculations at the CASSCF/6311G level of theory predicts that upon excitation the neutral ground state is planar and the energy spacing between the levels is very small. Preliminary calculations also predict torsional motion coupled to electronic modulations on the D$_{0}$ state and further calculations are being performed to ascertain the involvement of the D$_{1}$ and D$_{2}$ states. This could help us better understand the electronic effect of substitution on a benzene ring. [Preview Abstract] 

C1.00230: Excitation and photoionization of ultracold potassium atoms in the ACdriven magneto optical trap (ACMOT) John Agomuo, Andrew Murray, Matthew Harvey The operation of a new cold atom trap (the ACMOT) and its application in photoionization experiments is described. Ionization of cold K atoms in the ACMOT is discussed, the ionization proceeding in a stepwise fashion using a combination of infrared radiation with that from a blue diode laser. A significant limitation of magneto optical trapping (MOT) techniques has been the requirement to eliminate the magnetic fields prior to the interaction occurring. To address this, the ACMOT was invented in Manchester. This is a pulsed trap, so that the magnetic fields are completely eliminated prior to the electron interaction. Low energy electrons can then be extracted from laser photoionization. In this work, the potassium is cooled to $\sim$0.25mK. Photoionization proceeds by a stepwise route, atoms excited by the trapping laser at $\sim$766nm being ionized by radiation at $\sim$448nm. Both fluorescence from the atoms and the ion yield are used to determine details of the interaction. These techniques are being studied since it then is possible to create cold electron bunches of high coherence. A detailed description of the ACMOT, its operation and application will be presented. A new cold electron source being built in Manchester will also be discussed. [Preview Abstract] 

C1.00231: Efficient NonResonant Absorption of Electromagnetic Beams in Thin Cylindrical Targets: Experimental Evidence Andrey Akhmeteli, Nikolay Kokodiy, Boris Safronov, Valeriy Balkashin, Ivan Priz, Alexander Tarasevitch A theoretical possibility of nonresonant, fast, and efficient (up to 40 percent) heating of very thin conducting cylindrical targets by broad electromagnetic beams was predicted in [Akhmeteli, arXiv:physics/0405091 and 0611169] based on rigorous solution of the diffraction problem. The diameter of the cylinder can be orders of magnitude smaller than the wavelength (for the transverse geometry) or the beam waist (for the longitudinal geometry) of the electromagnetic radiation. This can be used for numerous applications, such as pumping of active media of shortwavelength lasers, e.g., through efficient heating of nanotubes with laser radiation. Experimental confirmation of the above results is presented [Akhmeteli, Kokodiy, Safronov, Balkashin, Priz, Tarasevitch, arXiv:1109.1626 and 1208.0066]. Significant (up to 6\%) absorption of microwave power focused on a thin fiber (the diameter is three orders of magnitude less than the wavelength) by an ellipsoidal reflector is demonstrated experimentally. For the longitudinal geometry, significant absorption (10\%) of the power of a wide CO2 laser beam propagating along a thin wire is demonstrated experimentally (the diameter of the wire is two orders of magnitude less than the beam waist width). [Preview Abstract] 

C1.00232: Laser cooling with threelevel cascade transitions: calculations for group I and II atoms Cruz Flavio, Michael Sundheimer, Wictor Magno From an interest in investigating laser cooling techniques suited for alkalineEarth atoms, we analyze twocolor laser cooling with threelevel cascade transitions. In particular, for the most abundant even isotopes of light elements such as magnesium and calcium, usual subDoppler techniques or narrowline cooling either cannot be applied or are too difficult to implement. For cascade transitions in which the upper level has longer lifetime than the intermediate one, and for cooling in a ``EIT fashion,'' e.g. using ``strong'' and ``weak'' lasers, we found that temperatures~below the Doppler limits associated with each one of~the individual transitions are expected. Here we present estimations of temperatures as function of detunings and laser intensities for alkalineEarth (Mg, Ca, Sr, Yb, Zn, Cd) and metalalkaline atoms (Rb, Cs, Na), which can be used to stimulate further experimental and theoretical work. We study the influence of coherences on the final temperatures, and the effect of phase fluctuations between the lasers. We also discuss an analysis of temperatures limits in terms of dressed states, which reveal a general and simpler method to estimate temperature limits in threelevel cooling. [Preview Abstract] 

C1.00233: Dissipative cavity optomechanics of levitated nanoparticles and nanodumbbells Steven Habraken, Wolfgang Lechner, Peter Zoller The interaction between dielectric particles and a laserdriven optical cavity gives rise to both conservative and dissipative dynamics, which can be used to levitate, trap, and cool nanoparticles. We analytically and numerically study a twomode setup in which the optical potentials along the cavity axis cancel, so that the resulting dynamics is almost purely dissipative. For appropriate detunings of the laser drives, this dissipative optomechanical dynamics can be used to sort particles according to their size, to rectify their velocities, and to enhance transverse cooling. We also consider dumbbells of dielectric nanoparticles and show that properly tuned optical parameters allow for the study of the nonequilibrium dynamics of composite nanoparticles with nonisotropic optical friction. We find optically induced ordering and nematic transitions with nonequilibrium analogs to liquid crystal phases for ensembles of dimers.\\ \\ $[1]$. S. J. M. Habraken, W. Lechner and P. Zoller, Phys. Rev. A 87, 053808 (2013). $[2]$. W. Lechner, S. J. M. Habraken, N. Kiesel, M. Aspelmeyer and P. Zoller, Phys. Rev. Lett. 110, 143604 (2013). [Preview Abstract] 

C1.00234: Controlling Thermal Collisions with FrequencyChirped Light Matthew Wright We conduct semiclassical montecarlo simulations of cold collisions utilizing frequencychirped laser light on the nanosecond timescale. Previous work revealed partial control of lightassisted collisional mechanisms with relatively slow chirp rates (10 GHz/$\mu$s). Collisions induced with positive chirped light enhance the inelastic collisional loss rate of atoms from a magnetooptical trap whereas these trap loss collisions can be blocked when negative chirped light is used. Early quantum and classical simulations show that for negative chirps the laser's frequency continually interacts with the atompair during the collision. We investigate how this process depends on the chirp rate and show that by moderately speeding up the chirp ($>$ 50 GHz/$\mu$s), we can significantly enhance the difference in the collisional loss rate induced by the negative and positive chirps, gaining nearly full control of the collision. We also explore extending this model to probe collisions at temperatures exceeding 1 K. [Preview Abstract] 

C1.00235: Temperature dependence of Rb(5$P)+$Rb(5$P)\to $Rb(6$P)+$Rb(5$S)$ energy pooling process S.J. Sweeney, J. McAndrew, J. Huennekens We describe recent progress on a cellbased experiment studying the temperature dependence of energy pooling collisions between excited rubidium atoms in a vapor. We create a thermal population of Rb(5$P_{J})$ atoms using a cw tunable diode laser tuned to the 5$S_{\mathrm{1/2}}\to $5$P_{\mathrm{1/2}}$ transition. Finestructure changing collisions populate the 5$P_{\mathrm{3/2}}$ state while energy pooling collisions between 5$P$ atoms (of either the same or different $J $value) will populate higher energy levels. We measure the 6$P_{J\prime }\to $5$S_{\mathrm{1/2}}$ fluorescence at right angles to the laser beam and normalize this signal to a combination of the 5$P_{\mathrm{3/2}}\to $5$S_{\mathrm{1/2}}$ fluorescence and 5$P_{\mathrm{1/2}}\to $5$S_{\mathrm{1/2}}$ fluorescence (proportional to each of the 5$P_{J}$ densities, respectively). Varying the temperature of the oven containing the rubidium cell allows us to map the temperature dependence of the Rb(5$P_{J})+$Rb(5$P_{J})\to $Rb(6$P_{J\prime })+$Rb(5$S_{\mathrm{1/2}})$ energy pooling rate coefficient. Our preliminary results indicate a temperature dependence does exist, but further work is required to verify these results. [Preview Abstract] 

C1.00236: Mutual neutralization at low collision energies: the power of imaging April K. Vassantachart, Shalynn L. Romano, Merl F. Martin, Vola M. Andrianarijaona, Xavier Urbain Mutual neutralization studies are generally limited to energies above a few eV, and do not specify the electronic state of the products, merely indicating a band of principal quantum numbers based on timeofflight intervals (Terao \textit{et al.}, Europhys. Lett. \textbf{1} (1986) 123). We upgraded our merged beam setup to reach meV collision energies, and incorporated threedimensional product imaging. Besides providing clear coincidence signals, this technique gives unambiguous identification of the electronic states of the products. Knowing their angular distribution at the different collision energies allows absolute cross sections to be retrieved. Results for the H$^{+}$/H$^{}$ and He$^{+}$/H$^{}$ systems will be presented, providing detailed branching ratios for nondegenerate channels. [Preview Abstract] 

C1.00237: Infrared Signatures of Laser Induced Plasma in Air Alexandru Hening, Ryan Lu, Ayax Ramirez Characterization of the temporal and spatial evolution of laser generated plasma in air is necessary for the development of potential applications which range from laser induced ionized micro channels and filaments able to transfer high electric pulses over few hundreds of meters, to the generation of plasma artifacts in air, far away from the laser source. This work is focused mainly on the infrared spectrum. The influence of laser parameters (energy per pulse, pulse duration, repetition rate, wavelength and etc.) on the plasma formation and evolution has been investigated. Laser transmission losses through the air as well as through the breakdown plasma as well as their effect on infrared plasma signature are to be presented. [Preview Abstract] 

C1.00238: QUANTUM INFORMATION, CONCEPTS AND COMPUTATION 

C1.00239: Verification of Quantum Processes in a Functional Based Programming Language Anthony Hoover As the complexity and scope of prospective quantum programs increases, it becomes more and more important that program developers have a method of testing whether the code that they are developing is working in the way intended. It has been determined that an effective method of procedure verification for quantum processes involves exhaustively generating input states for the procedure and comparing the output states to what we would expect. In this project, Haskell code has been developed that utilizes these methods and exhaustively verifies a program's reliability with little effort required by the user. [Preview Abstract] 

C1.00240: Origin of the Flux Noise in Superconducting Quantum Interference Devices Hui Wang, Clare C. Yu, Ruqian Wu Quantum computers hold out the promise of being massively parallel and thus performing calculations much faster than conventional computers. A major obstacle for reliable quantum computation is flux noise generated by fluctuating magnetic spins in qubits. It is thus crucial to find out the microscopic origin of spins. In this work, we find that these spins result from the surfaceinduced magnetism, through systematic density functional theory calculations. Both O2 adsorbates and Al vacancies can produce spontaneous magnetization on the Al2O3(0001) surface. Meanwhile, the magnetic anisotropy energies are extremely small. These results explain the origin of flux noise on Al qubits. [Preview Abstract] 

C1.00241: Twophoton Rabi oscillations in a superconducting transmon qubit DongGwang Ha, Jung Hwan Park, SeungBo Shim, Woon Song, Yonuk Chong We report our detailed measurement of twophoton Rabi oscillations in superconducting transmon qubit. For a transmon qubit, twophoton process has the advantage that it allows the direct transition from the ground state to the second excited state, which is forbidden in the dipole transition by the selection rule. We demonstrate twophoton Rabi oscillations in a superconducting transmon qubit made of Al/AlOx/Al Josephson junction. The qubit is strongly coupled to a threedimensional superconducting aluminum resonator, and the quantum state population is measured through the cavity readout in the strong dispersive regime. In twophoton Rabi oscillation, its dependence on the driving microwave power and the frequency is in good agreement with the theoretical expectation. We will also show the measurement of the ac Stark shift from strong qubit drive for both one and twophoton Rabi oscillations. [Preview Abstract] 

C1.00242: NonEquilibrium Quantum Phases In The JaynesCummings Lattice Marius Constantin, Devin Underwood, Andrew Houck With the ability to control disorder in microwave cavity lattices (Underwood2012), superconducting circuits provide a feasible platform to conduct onchip strongly correlated manybody experiments (Houck2012). We aim to fabricate a lattice of dispersive JaynesCummings models by strongly coupling a microwave resonator to a superconducting qubit at each site. The high Q lattice will allow us to investigate the nonequilibrium steady state regime of an open quantum system driven continuously. It was theoretically shown that the lattice's hybrid elementary excitations exhibit distinct quantum phases (Koch2009), including the Mott insulator and the superfluid phases. Experimentally, we intend to perform quantum nondemolition measurements of photon statistics by coupling a measurement qubit to the central lattice site (Johnson2010). In the Mott insulator phase, the statistics of the photon number in the center resonator exhibit the characteristic absence of quantum fluctuations while the superfluid phase is consistent with poissonian statistics of the photon number. The superfluid phase is also characterized by the high correlation between two nonadjacent edge lattice sites, signaling the presence of longrange offdiagonal order (Bozyigit2011, Angelakis2007). [Preview Abstract] 

C1.00243: Josephson Phase Qubit with a Distributed Reactance: Theory David Ferguson, Anthony Przybysz, Ofer Naaman, Joel Strand, James Medford, Aaron Pesetski Recently, the Northrop Grumman's superconducting systems team designed, fabricated, and measured a novel phase qubit in which the shunt capacitance across the Josephson junction and the inductance of the SQUID are provided by a microstrip resonator. To account theoretically for this novel design we treat the superconducting phase drop along the microstrip's length as a continuous field. We present an analysis of this model, describing how the normal modes of the coupled system are influenced by both the applied flux and the microstrip's termination impedance, and how the nonlinear coupling of the fundamental ``qubit mode'' to higher modes generates significant renormalizations of mode frequencies and anharmonicities. [Preview Abstract] 

C1.00244: Protected Flux Pairing Qubit Matthew Bell, Wenyuan Zhang, Lev Ioffe, Michael Gershenson We have studied the coherent flux tunneling in a qubit containing two submicron Josephson junctions shunted by a superinductor (a dissipationless inductor with an impedance much greater than the resistance quantum [1]). The two low energy quantum states of this device, ${\left0\right\rangle}$ and ${\left1\right\rangle}$, are represented by even and odd number of fluxes in the loop, respectively. This device is dual to the charge pairing Josephson rhombi qubit [2]. The spectrum of the device, studied by microwave spectroscopy, reflects the interference between coherent quantum phase slips in the two junctions (the AharonovCasher effect). The time domain measurements demonstrate the suppression of the qubit's energy relaxation in the protected regime, which illustrates the potential of this flux pairing device as a protected quantum circuit. \\[4pt] [1] M. Bell et al., ``Quantum Superinductor with Tunable Nonlinearity,'' PRL 109, 137003 (2012). \\[0pt] [2] S. Gladchenko et al., ``Superconducting Nanocircuits for Topologically Protected Qubits,'' Nature Physics 5, 48 (2009). [Preview Abstract] 

C1.00245: Searching for Quantum Contextual Models Adam Rosier, Scott Walck, David Lyons Quantum states may be classified in a number of ways; of particular interest are quantum states that exhibit the property of contextuality. This research presents an outline and attempts to establish a framework inside of which it may be possible to determine whether or not a given quantum state exhibits contextual behavior. As an example, through a trialanderror approach it has been determined that 3, 4, and 5qubit Werner states are highly unlikely to exhibit contextuality. Additionally, a model is proposed in an effort to help illuminate possible quantum states that may be tested. [Preview Abstract] 

C1.00246: Snapping single flying photons based on tunneling assisted multiphoton absorption Zhengyong Li, Clemens Matthiesen, Chongqing Wu, Mete Atature Multiphoton absorption (MPA) can be used to measure the temporal correlation of flying photons at a much shorter timescale within a maximum delay (about 1$^{\mathrm{\thinspace }}$fs) given by the Heisenberg principle. We first measure the 2PA and 3PA of GaAsP material by using a mode locked laser (Mira 900) with pulse width less than 100 fs (76 MHz), and obtain pronounced 2PA and 3PA at 60 mW and 130 mW respectively (wavelength: 900 nm). We further strengthen the absorption process by using an extra electrical field through photon assisted tunneling, and double the MPA coefficient by a bias voltage of 5 V. Then, we demonstrate the tunneling assisted MPA in GaAsP by a pumpprobe scheme, and successfully snap flying single photons in 1550nm telecom band by using a synchronous 900nm fs sampling pulse train, which scanning the flying photons through a motorizing translation stage. Experimental results show that the timedomain width of the single photon is around 250 fs, and further statistical investigations demonstrate that the single photons follow subPoisson distribution with Mandel Q parameter of about 0.2, which means the photons are antibunching definitely. [Preview Abstract] 

C1.00247: Experimental twophoton absorption in silicon avalanche photodiode for infrared single photon detection Yani Zuo, Zhengyong Li, Ge Zhang, Zheng Yang, Weihua Liu, Chongqing Wu As an indirect band gap material, silicon avalanche diode (Si APD) possesses much more interesting features in nonlinear absorption especially the twophoton absorption (TPA). We experimentally investigate in detail the TPA in Si APD for infrared photons with different frequency, intensity, under different bias voltage. For frequency from 186.3 to 196.1 THz, the TPA rate goes up and then decreases at an optimal frequency around 172 THz for the APD under test. We further observe, for the first time according to our knowledge, that the TPA rate actually goes down when photon intensity exceeds a certain value, which is satisfied with the theoretical prediction given in Phys. Rev. B 77, 125219, that is, the TPA probability is affected by the dressinginduced energy level detuning. Moreover, we find that the TPA process is sensitive to the polarization state of the input photons, which can cause the absorption rate change over 15{\%}. Based on the TPA in Si APD, we successfully detect the infrared single photons at 1310nm with high quantum efficiency (65{\%}) at room temperature assisted with a 1550nm pump laser. [Preview Abstract] 

C1.00248: Measurementdeviceindependent quantum key distribution with uncharacterized qubit sources ZhenQiang Yin Measurementdeviceindependent quantum key distribution (MDIQKD) is proposed to be secure against any possible detection attacks. The security of the original proposal relies on the assumption that the legitimate users can fully characterize the encoding systems including sources. Here, we propose a new MDIQKD protocol where we allow uncharacterized encoding systems as long as qubit sources are used. A security proof of the new MDIQKD protocol is presented that does not need the knowledge of the encoding states. Simulation results show that the new scheme is practical. [Preview Abstract] 

C1.00249: Scaling of Entanglement Entropy in Point Contact Free Fermion Systems Bassir Caravan, Gregory Levine, Barry Friedman The scaling of entanglement entropy is computationally studied in several $1 

C1.00250: The Conceptual Foundation of a Practical Experiment to Obtain Distinct WhichWay and NonWhichWay Distributions at a Distance Using Delayed Choice and Without Correlating Measurement Results on Entangled Entities Douglas Snyder For a pair of entangled signal idler photons, one may ``lose'' the idler photon that carries whichway information and provides whichway information to the entangled signal photon before the signal photon is detected, thereby losing the entanglement. Over a number of runs, the result is an overall nonww distribution of the signal photons. If instead the idler photon is not lost, the idler photon continues to supply ww information to the signal photon and over a number of runs the result is an overall ww distribution of the signal photons. These different overall distributions of signal photons do not depend on correlating detections of the entangled paired signal idler photons. The experiment allows for a delayed choice on the idler photons to determine the distribution of distant signal photons (either overall ww or overall not ww) without having to make correlations between signal and idler photon detections. [Preview Abstract] 

C1.00251: A Proposed Experiment to Test Whether or Not the Reduced Density Matrix is Applicable to Entangled Particles Where the States of One of the Particles Relevant to the Entanglement are Eliminated before Any Detections are Made Douglas Snyder It is shown theoretically that the reduced density matrix is not applicable to the case where the states of one of two entangled particles relevant to the entanglement of the particles, and which provide ww info to the other particle, are eliminated before any particle detections are made. Instead, the entanglement is eliminated and the particle whose states are not eliminated enters into a pure state. A proposed experiment where this case (option 1) is tested is presented. The experiment has a second option (option 2) in which the states of both of the entangled particles that are relevant to the entanglement are preserved. In the experiment, the entangled particles become spatially separated. Elimination of the states of one of the entangled particles relevant to the entanglement results in the elimination of the entanglement and the placement of the other particle into a pure state. We have a delayed choice with regard to the particle whose states can be eliminated that affects the overall distribution (either reflecting interference or ww info) of the other particle that it is initially entangled with and that becomes physically distant from it. If the overall distribution of the signal photons in option 1 exhibits fringes and the overall distribution of the signal photons in option 2 is characteristic of ww info, then the reduced density matrix is not applicable to the case where the states of the signal photon relevant to the entanglement are eliminated before any detections are made. [Preview Abstract] 

C1.00252: Electron Diffraction by Benzene Molecule in Real Time Kyle Sherbert, JiaAn Yan By solving the timedependent Schr\"{o}dinger equation in real space and in real time, we study the electron diffraction by a benzene molecule ($C_{6}H_{6}$). Due to the wave nature of the electron, the scattered wave packet forms interesting diffraction patterns. The possibility of reconstructing the molecular structure from these patterns will be discussed. [Preview Abstract] 

C1.00253: Topological phase transition in a tunable onedimension chain of superconducting transmission line resonators Xiuhao Deng, Chunjing Jia We designed a simulator of BoseHubbard model based on tunable superconducting chain to realize the phase transition to topological MottInsulator(TMI). It is formed of transmission line resonators(TLR) with tunable eigenenergy coupled with superconducting quantum interference device(SQUID). This chain can be fabricated into a loop structure so that periodic boundary condition can be applied. In this way, an equivalent superlattice chain arises by adjusting different TLR eigenenergies and coupling energies between them. Phase transition can be realized due to the tunability in superconducting circuit. Benefiting from the tunability and the loop structure, exact diagonalization technique can be implemented in the numerical solution in order to obtain the phase diagram. Also, different kinds of superlattice structures can be engineered to broaden the study of criticality. There are some interesting critical phenomenons in the phase diagrams worth of further discussion. [Preview Abstract] 

C1.00254: Shortcuts to adiabaticity in classical and quantum processes for scaleinvariant driving Sebastian Deffner, Christopher Jarzynski, Adolfo del Campo All real physical processes in classical as well as in quantum devices operate in finitetime. For most applications, however, adiabatic, i.e. infinitelyslow processes, are more favorable, as these do not cause unwanted, parasitic excitations. A shortcut to adiabaticity is a driving protocol which reproduces in a short time the same final state that would result from an adiabatic process. A particular powerful technique to engineer such shortcuts is \textit{transitionless quantum driving} by means of counterdiabatic fields. However, determining closed form expressions for the counterdiabatic field has generally proven to be a daunting task. In this paper, we introduce a novel approach, with which we find the explicit form of the counterdiabatic driving field in arbitrary scaleinvariant dynamical processes, encompassing expansions and transport. Our approach originates in the formalism of generating functions, and unifies previous approaches independently developed for classical and quantum systems. We show how this new approach allows to design shortcuts to adiabaticity for a large class of classical and quantum, singleparticle, nonlinear, and manybody systems. [Preview Abstract] 

C1.00255: Information driven current in a quantum Maxwell demon Sebastian Deffner We describe a minimal model of a quantum Maxwell demon obeying Hamiltonian dynamics. The model is solved exactly, and we analyze its steadystate behavior. We find that writing information to a quantum memory induces a probability current through the demon, which is the quantum analog of the classical Maxwell demon's action. Our model offers a simple and pedagogical paradigm for investigating the thermodynamics of quantum information processing. [Preview Abstract] 

C1.00256: Quantum speedup in memory environment ZhenYu Xu, Shunlong Luo, W.L. Yang, Chen Liu, Shiqun Zhu Memory (nonMarkovian) effect is found to be able to accelerate quantum evolution [S. Deffner and E. Lutz, Phys. Rev. Lett. 111, 010402 (2013)], for the intrinsic quantum speed limit time is decreased when the nonMarkovianity becomes stronger. In this work, for an atom in a structured reservoir, we show that the mechanism for the speedup is not only related to nonMarkovianity but also to the population of excited states under a given driving time. In other words, it is the competition between nonMarkovianity and population of excited states that ultimately determines the acceleration of quantum evolution in memory environment. A potential experimental realization for verifying the above phenomena is discussed by using a nitrogenvacancy center embedded in a planar photonic crystal cavity under the current experimental conditions. [Preview Abstract] 

C1.00257: Counterfactual Measurements and the Quantum Zeno Effect Onofrio Russo, Liang Jiang The apparent paradoxical paradigm of an interaction free measurement (counterfactual measurement) of the presence of a classical or quantum object without any scattering or absorption of photons is considered in light of the quantum Zeno effect. From one perspective, the counterfactual measurement in principle is consistent with minimizing the interaction between the object and the photon. However, the quantum Zeno effect mandates that repeated interactions with photons (although weakly coupled) are required and necessary to inhibit the coherent evolution of the state of the system. We consider and appraise these seemingly conflicting concepts. [Preview Abstract] 

C1.00258: Nonlinear Single Spin Spectrum Analyzer Shlomi Kotler, Nitzan Akerman, Yinnon Glickman, Roee Ozeri Qubits have been used as linear spectrum analyzers of their environments, through the use of decoherence spectroscopy. Here we solve the problem of nonlinear spectral analysis, required for discrete noise induced by a strongly coupled environment. Our nonperturbative analytical model shows a nonlinear signal dependence on noise power, resulting in a spectral resolution beyond the Fourier limit as well as frequency mixing. We develop a noise characterization scheme adapted to this nonlinearity. We then apply it using a single trapped ion as a sensitive probe of strong, nonGaussian, discrete magnetic field noise. Finally, we experimentally compared the performance of equidistant vs Uhrig modulation schemes for spectral analysis. Phys. Rev. Lett. 110, 110503 (2013). Synopsis at http://physics.aps.org/synopsisfor/10.1103/PhysRevLett.110.110503 [Preview Abstract] 

C1.00259: Two Dimensions of Time could produce a New Supersymmetric Theory Richard Kriske In the collapse of a system into the eigenstate of an operator,a new type of time, call it ``information time,'' could be inferred. One could look at this time to evolve the quantum state as a type of ``mass.'' This would be a correction to the explaination to the existing Higgs mechanism. Likewise one could see the dual of this in the Dilation in ``clock time'' seen in Special Relativity. In other words we see a time Dilation in ``Information Time'' as being a delay in Acceleration which we call ``mass.'' The two types of Time are Duals to each other and are symmetric. The second dimension of time has been overlooked for this reason. Time Dilation is the dual to persistance of the collapse of a system. This Duality produces some interesting and measurable effects. One conclusion that one can draw from this ``Symmetry'' is that there is a noncommuting set of operators, and a particle that connects the two ``Perpendicular" time axis. We know from classical Quantum Theory that Momentum and Position do not commute, and this is something like the Noncommuting Time Dimensions, in that Momentum has a timelike construction and Position has a Space like construction, it is something like x, and t, not Commuting. What is the Conserved Quantity between the two types of time, is it Energy? [Preview Abstract] 

C1.00260: Quantum Time of Arrival Calvin Stubbins A novel approach to the time of arrival probability distribution is discussed. This method is universal in the sense that it can be used for any potential. As an example, this algorithm is used to calculate the time of arrival for a one dimensional free particle gaussian wave packet. The quantum time of arrival problem is illustrated by the following question: If at time $t=0$ a particle localized at $x=0$ is described by the state $\psi(t)\rangle$, when is it registered by a detector placed at $x=L$? The approach used in this study is to decompose the state vector into a superposition of orthonormal states that consist of a position eigenstate and a complementary state. Repeated interactions with the detector cause the state vector to evolve as a Markovian process. At each interaction with the detector, the state vector either collapses to the position eigenstate or to a complementary state. The detector state is modeled by randomly centering the position eigenstate according to a gaussian distribution that has the same width as the particle detector. After each interaction, the probability that a detection is made is calculated. This results in a probability distribution for the arrival time. [Preview Abstract] 

C1.00261: Quantum Superposition, Collapse, and the Default Specification Principle Armin Nikkhah Shirazi Quantum Superposition and collapse lie at the heart of the difficulty in understanding what quantum mechanics is exactly telling us about reality. We present here a principle which permits one to formulate a simple and general mathematical model that abstracts these features out of quantum theory. A precise formulation of this principle in terms of a settheoretic axiom added to standard set theory may directly connect the foundations of physics to the foundations of mathematics. [Preview Abstract] 

C1.00262: On the Unique Identification of the Polar Optical Kerr Effect with Microscopic TimeReversal Symmetry Breaking Alexander Fried Over the past few decades, there has been an ongoing discussion regarding the choice of electromagnetic constitutive relations which correctly model linear media that exhibit natural optical activity, with most recent debate involving applications to optical phenomena in chiral superconductors and other gyrotropic media. In particular, is the controversy as to whether light incident upon naturally active materials will exhibit nonreciprocal polarization rotation in reflection, also known as the magnetooptical Kerr effect. A variety of constitutive relations have been postulated which describe the Electrodynamics within such materials, but only some of them predict this phenomena, while experimental investigations have similarly yielded mixed results. One such experiment uses a modified Sagnac Interferometer for high resolution and unique measurements of the Kerr effect and also has the property that it inherently tests for ``reciprocity,'' a metrological symmetry wherein the results of a measurement are the same as when an optical source and an optical detector are interchanged. We demonstrate theoretically and experimentally that the Sagnac Interferometer only measures timereversal symemtry breaking and that gyrotropic materials can not give rise to a Kerr Effect. [Preview Abstract] 

C1.00263: GENERAL THEORY/COMPUTATIONAL PHYSICS 

C1.00264: An ntiered model of fundamental structure Aran David Stubbs Here, the elementary particles consist of 2 gravitons as tachyons in 1s orbits and protomatter in higher s orbits. Each electron consists of 3 protophotons, a protolepton, and 2 gravitons. This protolepton has 6 inframatter bits: 3 tachyons and 3 luxons in s orbits. The tachyons have v about 10$^{24}$c, with significant L we interpret as charge. The nucleus consists of monoquarks, diquarks, and a photonlike shell. Each has 2 gravitons plus protomatter: 1 protoquark per monoquark, 2 protoquarks per diquark, and a protopion each. Some also have protophotons, as does the shell. The protopion has trivial color and the protophoton has trivial charge. The protoquark has charge bits in s orbits and color bits in p orbits. The porbits each have net L on the x/y plain where charge is L on the zaxis. As the p orbits are eccentric, only solutions with vectors with the 3 tachyons either $60^{\circ}$ or $120^{\circ}$ apart produce constant angular momentum. The $60^{\circ}$ solution produces net color. Eccentricity is $e=l\sqrt 2 /2n$ for luxon Energy $E_{n,l} =E_{1s} n^{3}/(n^{2}l^{2}/2)$and tachyon $E_{n,l} =E_{1s} n^{5}/(n^{2}l^{2}/2)^{2}$ so 4.017KeV 1s energy for the charge bits and 2.981MeV 1s energy for the color bits. [Preview Abstract] 

C1.00265: Accelerated Monte Carlo Methods for Coulomb Collisions Mark Rosin, Lee Ricketson, Andris Dimits, Russel Caflisch, Bruce Cohen We present a new highly efficient multilevel Monte Carlo (MLMC) simulation algorithm for Coulomb collisions in a plasma. The scheme, initially developed and used successfully for applications in financial mathematics, is applied here to kinetic plasmas for the first time. The method is based on a Langevin treatment of the LandauFokkerPlanck equation and has a rich history derived from the works of Einstein and Chandrasekhar. The MLMC scheme successfully reduces the computational cost of achieving an RMS error $\epsilon$ in the numerical solution to collisional plasma problems from $\mathcal{O}(\epsilon^{3})$  for the standard stateoftheart Langevin and binary collision algorithms  to a theoretically optimal $\mathcal{O}(\epsilon^{2})$ scaling, when used in conjunction with an underlying Milstein discretization to the Langevin equation. In the test case presented here, the method accelerates simulations by factors of up to 100. We summarize the scheme, present some tricks for improving its efficiency yet further, and discuss the method's range of applicability. [Preview Abstract] 

C1.00266: Chaotic dynamics of a onedimensional plasma Pankaj Kumar, Bruce Miller The dynamics of a onedimensional periodic plasma is investigated with $N$body simulations using an eventdriven algorithm. The algorithm is based on analytic expressions for the electric field and potential in the periodic plasma that makes it possible to follow the time evolution of the plasma exactly without resorting to numerical approximations. The temperature dependence of the largest Lyapunov exponent of the plasma is investigated by employing an efficient approach for defining the phasespace distance appropriate for systems with periodic boundary. The approach allows for the unambiguous testorbit renormalization in phase space required to calculate the Lyapunov exponent. The results show evidence of a characteristic transition in the chaotic behavior of the plasma near a specific temperature in the thermodynamic limit. [Preview Abstract] 

C1.00267: Quantum Particle Dynamics in a Highly Singular $1D$Potential $U(x)=\alpha \delta(x)+\beta\delta^{\prime}(x)$ Superposed on a WellBehaved One Norman J.M. Horing, Jay D. Mancini We examine the onedimensional quantum dynamics of a Schr\"{o}dinger particle in a potential represented by a generalized function of the form $U(x)=\alpha\delta(x)+\beta d\left( \delta(x)\right) /dx$ superposed on a well behaved potential $V(x)$. In this, we construct the full, exact Green's function for such a $1D$ system analytically in closed form, taking account of a spatially variable mass $m(x)$. Our result shows that there can be no electron transmissions through the $\beta\delta^{\prime}(x)$ potential, regardless of the presence of the $V(x)$ potential and $\alpha\delta(x)$, (with $\alpha\neq0$). [Preview Abstract] 

C1.00268: Iterative Variational Ansatz for the Hubbard Model J.D. Mancini, V. Fessatidis, R.K. Murawski, S.P. Bowen A number of years ago Eichenberger and Baeriswyl [Phys.~Rev. B \textbf{76}, 180504(R) (2007)] (EB) introduced a novel variational ansatz for the study of the (repulsive) Hubbard model on a square lattice. Taking the Hubbard Hamiltonian to be $\hat{H}=t\hat{T}+U\hat{D}$ (where $\hat{T}$ and $\hat{D}$ are the usual Hubbard hopping and Coulomb terms, respectively), EB chose their variational trial function to be $\left\vert \psi\right\rangle =e^{h\hat{T}% }e^{g\hat{D}}\left\vert \psi_{0}\right\rangle $ where $h$ and $g$ are variational parameters. In this work we will consider moments of the Hamiltonian $h_{n}=\left\langle \psi_{0}\right\vert H^{n}\left\vert \psi _{0}\right\rangle =\left\langle 0\right\vert e^{\alpha\hat{\Gamma}}% H^{n}e^{\alpha\hat{\Gamma}}\left\vert 0\right\rangle \approx\left\langle 0\right\vert \left( 1\alpha\hat{\Gamma}\right) H^{n}\left( 1\alpha \hat{\Gamma}\right) \left\vert 0\right\rangle $, where $\alpha$ is a real parameter. Following EB we choose $\hat{\Gamma}=\hat{T}+\hat{D}$. Sequentially we minimize $h_{n}$ with respect to $\alpha$ for increasing values of $n$ in order to optimize the Hamiltonian moments. Preliminary results are given. [Preview Abstract] 

C1.00269: ABSTRACT WITHDRAWN 

C1.00270: Induced changes in surface bonding by Electric Field: Integrating First Principles and Atom Probe Tomography Joaquin Peralta, Claudia Loyola, Scott Broderick, Krishna Rajan Evaporation field is a phenomenon that occurs when surface atoms start to evaporate with the presence of a strong electric field. This is utilized in Atom Probe Tomography (APT), by a voltage over a specimen tip. The evaporation of these ionized atoms allow us to generate a three dimensional reconstruction of the specimen. Despite the big amount of information extracted from APT, the phenomenology of the process in an atomic level has not been widely studied. In this work we investigate the evaporation process on an Al$_3$Sc surface under the presence of a strong electric field by using DFT with QuantumEspresso software. The chosen surface contains a slab of 80 atoms of Al$_3$Sc in the $<111>$ direction along the $z$axis. The calculations were performed with four different configuration of adatoms on the surface: Al, Sc, AlAl, AlSc. The electric field is applied slowly to the surface up to 36 V/nm. The distance of the adatom or dimer to the surface is not modified during the simulation. The charge density between these and the surface is determined. This work describes an exhaustive analysis of the charge bonding of the adatoms and the surface with the presence of a strong electric field. Variations of the bonding are clearly observed and related to detected ions in APT. [Preview Abstract] 

C1.00271: The Energy flow of a Linear Dipole in a Dielectric Medium George Hinerman, Xin Li, Henk Arnoldus The energy flow lines of radiation emitted by a linear dipole in free space are radially straight. This is observed by analyzing the field lines of the Poynting vector. When a linear dipole is placed in an energy absorbing medium, such as water, the field lines begin to exhibit a partial curvature. Our research shows that due to the damping in a dielectric medium, the direction of the energy flow lines are altered in the near field. The curved field lines in the near field; however, do not contribute to energy flow in the far field. Energy flow patterns of linear dipole radiation in different mediums will be discussed. [Preview Abstract] 

C1.00272: Selfconsistent continuum solvation of electrodes in electrochemical environments Stephen Weitzner, Ali Kachmar, Ismaila Dabo Implicit solvent models have been widely used to study quantum systems in solutions. Nevertheless, these models differ considerably in their phenomenological details and in the complexity of their parameterization. While conventional implicit models rely on atomic positions and tabulated atomic radii to construct the solvation shell that surrounds the quantum solute, recent models aim to reduce the number of parameters by building solvation shells directly from the computed electronic densities. The selfconsistent continuum solvation (SCCS) model, which belongs to this latter class, has been shown to reproduce the solvation energies of a wide range of molecular species in very satisfactory agreement with experiment, using only two fitted parameters [J. Chem. Phys. 136, 064102 (2012)]. Here, we report on the performance of the SCCS model in describing the electrical properties of quantum electrodes embedded in continuum electrolytes. We show that one additional parameter is necessary to capture experimental shifts in the neutral electrode potential as a function of surface composition and structure, and to correctly calibrate computed results to a common electrochemical reference. Directions for further improvement are also discussed. [Preview Abstract] 

C1.00273: ABSTRACT WITHDRAWN 

C1.00274: From rectangleshaped to squareshaped antennas based on graphene: Tshaped, Crossshaped and Rectangleshaped Structure Transitions Victor A. RodriguezToro, Lucas H. Gabrielli, Hugo Fragnito, Hugo E. HernandezFigueroa The absorbing cross section (ACS) for graphenebased terahertz antennas is calculated for different shapes. All structures are wide enough so that edge effects can be neglected. A general Kubo form considering only intraband transitions approximates the material conductivity for graphene, while its relative permittivity and permeability are kept at 1. Being valid in a frequency range between 0.5THz and 4THz, we use this model to find the frequency at which the maximum ACS is reached for each of the analyzed antenna shapes. In this exploration, we numerically study the performance of arbitrary rectangular, T and crossshaped antennas. These results can also be useful for the design of complex graphenebased metamaterials operating in the terahertz range. [Preview Abstract] 

C1.00275: First principles approaches for the structure searching in thermoelectric GeAgSbTe alloys Hikari Shinya, Hiroki Funashima, Akira Masago, Tetsuya Fukushima, Hiroshi KatayamaYoshida Since the discovery of a discontinuous decreasing of the thermal conductivity without changing of the electric conductivity in quaternary AgSbTe$_2$GeTe (TAGS) alloys by Skrabek and Trimmer[1], the TAGS alloys have attracted much attention as the good thermoelectric materials. However, the mechanism of the dramatic change of thermal conductivity has yet to be understood, and even the crystal structures of the TAGS alloys are still under discussion. In this talk, to shed light on this problem, we investigate the electronic structures of Ag and Sb doped GeTe by firstprinciples calculations[2], and also perform the structure searching in the quaternary TAGS alloys by a multicomponent cluster expansion method[3]. We will discuss an important correlation between the crystal structure and the anomalous thermal conductivity based on our calculation results. [1] E. Skrabek and D.Trimmer, U.S. Patent No. 3945855 (23 March 1976). [2] G. Kresse and D. Joubert, Phys. Rev. B, 59, 1758 (1758). [3] A. van de Walle et al., CALPHAD: Comput. Coupling Phase Diagrams Thermochem. 26, 539 (2002). [Preview Abstract] 

C1.00276: Effect of anode morphology on charging rate in Lithium Ion Batteries Ning Sun, Dilip Gersappe Carbon materials such as graphite are widely used in Lithium Ion Batteries as an active component for the anode. We set up a 3D Lattice Boltzmann model to simulate the intercalation reaction of graphite anode during charging process. Our model considered the mass transfer both inside and outside of anode, and the equilibrium potential drop of the anode material as a function of local charge amount. By using a simple spherical anode morphology, we tested the shrinking core model. Our simulation showed the influence of current density and diffusion speed of Li ion in the graphite phase on phase boundary movement and determined when the outer layer of anode is fully charged. We further developed our anode morphology to a random particle model, and studied the influence of current density and porosity of anode on the total charge of the system. Our results show that it is possible to obtain both high charging capacity and charging rate by adjusting the morphology of anode. [Preview Abstract] 

C1.00277: Density Functional Theory on the Studies of Lithium Battery Materials Bo Wang, Sijie Luo, Donald Truhlar Computational studies on the electrode materials in lithium batteries provide crucial information on the structure change and charge flow during the charging and discharging processes. Among various theoretical methods, KohnSham theory provides the best compromise between the accuracy and the computational cost. In the present study, we tested several new density functionals on the lithiumcontaining materials. M06L and N12, which have already shown good performance in a variety of databases, outperform the widely used PBE functional to reproduce the experimental structures and averaged intercalation potentials. Especially, M06L functional gives similar performance as HeydScuseriaErnzerhof hybrid functional, but with less computational cost. Partial atomic charges provide a very convenient way to describe the charge distribution within molecules and crystals, and they are useful as an analysis tool that reflects charge flow during charging and discharging processes. In the present study, we validated CM5 charge model on a set of small molecules and derived CM5 partial atomic charges of a set of lithium compounds to understand the charge flow during electrochemical processes. Moreover, we applied the new tools to explore some new promising lithiumcontaining compounds. [Preview Abstract] 

C1.00278: A GPUassisted Semiclassical Study of FewBody Systems with Fractional Statistics Chester Chu, Eric Heller, Tobias Kramer In two spatial dimensions, quantum mechanical particles can be anyons that have fractional exchange statistics that lies between~ bosons and fermions. The energies and eigenstates of the fewbody problems for anyons is solvable analytically only for some limited cases. In this study, we present a novel approach for obtaining the energies and eigenstates for general fewparticle anyonic systems based on the semiclassical initial value representation method. We also demonstrate how GPU computing can be implemented for the semiclassical wave packet simulations. [Preview Abstract] 

C1.00279: Numerical Tribute to Achievement of Euler Carlos FigueroaNavarro, Mart\'In Eduardo MolinarTabares, Lamberto CastroArce, Julio Cesar CamposGarc\'Ia This work aims to make a tribute to one of the world's brightest personalities as it was the mathematical physicist Leonhard Euler (17071783). Some results where the influence of Euler persists with the novelty of applying numerical analysis using Matlab are here exposed. A first analysis was done with the series that defines Euler numbers and polynomials of FrobeniusEuler; another result is the characterization of the functions that carry to EulerMacheroni constant. In hydrodynamics is also feasible to evaluate graphically the relationship between dimensions in diameter and the exit angle of the height of Euler for turbomachines. In differential equations of CauchyEuler solutions for the cases of distinct real roots and complex roots are generated. Furthermore we report the generation of the Fourier series and the Fourier transform calculated by using Direct Commands of Matlab. In variational calculus it is possible to obtain plots from a problem of the Euler Lagrange equations. Finally, the Euler function is analyzed. Our purpose is to present a tribute to this giant of science also it could be an excuse to study his legacy by utilizing modern computational techniques. [Preview Abstract] 

C1.00280: A Two Frequency Gun for High Current Thermionic Cathode Electron Injection Systems for an FEL Jon Edelen, Sandra Biedron, John Harris, Stephen Milton, John Lewellen When an ungated thermionic cathode is operated in an RF gun, some fraction of the emitted electrons will return to the cathode due to the change in sign of the electric field in the gun. This backbombardment current causes heating of the cathode, and this reduces the ability of the cathode heater to control the bunch charge. In this paper, we investigate the use of a two frequency $TM_{010}$/$TM_{020}$ electron gun to mitigate this effect. Simulations revealed that for a 100pC bunch charge operating at 10MV/m gradient the harmonic field produced a 63\% reduction in the backbombardment power. [Preview Abstract] 

C1.00281: \textit{Ab initio} investigation of the electronic properties of Hg$_{\mathrm{m}}$Te$_{\mathrm{n}}$ clusters Sachin Nanavati, Vijay Kumar, Ravindra Pandey, Ambesh Dixit Nanostructured HgTe quantum dots have attracted attention due to their potential applications in novel midinfrared (3  5 $\mu $m) wavelength photodetectors and other optoelectronic applications. HgTe bulk material is a semimetal with bandgap $\sim$ 0.3 eV, however at nanoscale, we observe drastic changes in the optical and electronic properties such as band gap opening, that makes it possible for engineering optoelectronic properties. We investigated the structural, optical, and electronic properties of Hg$_{\mathrm{m}}$Te$_{\mathrm{n}}$ (m $=$ n $=$ 12, 13, 33, and 34) nanoparticles using density functional theory and the pseudopotential method within the generalized gradient approximation. The structures are relaxed to achieve the stable configurations and corresponding electronic properties are calculated. We investigated the density of states, energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), binding energy, and the HgTe bond length variation as a function of the cluster size. We will discuss the changes in the electronic structure and optical properties for these clusters with respect to the cluster size variation. [Preview Abstract] 

C1.00282: Deflection of an Asymmetric Top Molecule in an Inhomogeneous Electric Field Jose Almaguer, Eric Heller Classically an asymmetric top molecule with an electric dipole moment will be deflected for almost all initial conditions. However, there is experimental evidence suggesting that this deflection may not occur quantum mechanically when the molecule is excited to a single rotational eigenstate in a high density of states region. It has been suggested that this is due to the center of mass of the molecule moving adiabatically on a single BornOppenheimer potential energy surface. We perform the deflection calculation quantum mechanically, semiclassically, and classically to investigate this claim. [Preview Abstract] 

C1.00283: Evolution of Entanglement in Holographic Systems Elizabeth Berrigan, Josephine Suh Entanglement~entropy for a spatial region can be used to measure quantum correlations between subsystems, but is notoriously difficult to calculate using conventional methods. Holographic duality enables one to calculate the entanglement entropy of a class of strongly interacting quantum manybody systems analytically using blackhole physics.~ Our goal is to use the holographic formulation of the entanglement entropy for a strip region to study the time evolution of a quenched system approaching equilibrium. The geometry of the strip is characterized by a parameter $\eta =$2n/d, where n is the dimension of the strip region and d is the total number of spatial dimensions, and by its size R. It has been shown that as the system evolves, for surfaces with $\eta \ge $1 there exists a regime in which the entanglement entropy grows linearly with respect to time. However, for $\eta $\textless 1 the story is more complicated and it is unclear whether the linear regime exists. It is our aim to clarify this issue. We found some important differences in the holographic description in contrast to other cases of $\eta $, and investigated how this affects the timeevolution of the entanglement entropy. [Preview Abstract] 

C1.00284: Parallelized MultiWorm Algorithm for Large Scale Quantum MonteCarlo simulations Takafumi Suzuki, Akiko MasakiKato, Kenji Harada, Synge Todo, Naoki Kawashima The quantum Monte Carlo (QMC) calculation is a powerful and accurate method for quantum many body interacting systems. In this study, we present a new algorithm for the worldline Monte Carlo method based on the Feynman path integral. While the worm algorithm (WA) [12] has been used widely because of its broader range of applicability, the parallelization of WA is not straightforward. We present a general QMC algorithm based on the directedloop algorithm [2] with the domain decomposition. This new algorithm is referred to as Parallelized MultiWorm Algorithm (PMWA). In PMWA, a large number of worms are introduced by controlling a fictitious transverse field. For a benchmark, we applied the PMWA to the hardcore BoseHubbard model on the square lattice, and computed the systemsize dependence of the Bosecondensation order parameter up to $L^{2}= 10240^{2}$ by using 3200 processors. The benchmark results showed high parallelization efficiency [3]. This indicates that the PMWA is suitable for parallelizing on a distributedmemory computer. [1] N. Prokof'ev, B. Svistunov and I. Tupitsyn, Sov. Phys. JETP 87, 310 (1998). [2] O. F. Sylju{\aa}sen and A. W. Sandvik, Phys. Rev. E 66, 046701 (2002). [3] A. MasakiKato, et al., arXiv:1307.0328 (2013). [Preview Abstract] 

C1.00285: ABSTRACT WITHDRAWN 

C1.00286: Multiscale simulation of plasmaobject interaction Oleg Batishchev We present first simulation results from 3D3V hybrid kinetic method. The combination of discrete and continuous representation of distribution function allows controlling numerical noise and diffusion. Adaptive 3D grid automatically follows regions of high gradient and discontinuities such as shocks, radiation fronts, doublelayers and sheaths. Our semianalytical approach [1] to fractional substeps exceeds implicit schemes in accuracy and numerical stability. [1] O.Batishchev, SemiAnalytical Adaptive Vlasov  FokkerPlanck  Boltzmann Methods, pp.237315, in book (Ed. M.Shoucri) Eulerian Codes for the Numerical Solution of the Kinetic Equations of Plasmas, Nova Science, 2010. [Preview Abstract] 

C1.00287: Numerical study of magnetic mirror effect on ultrafast wire ablation Alla Batishcheva, Oleg Batishchev, JeanLuc Cambier Ultrafast laser ablation of a microndiameter wire at relativistic intensities is simulated numerically. A soliddensity plasma cluster is placed into strong magnetic field [1], which is directed along the wire axis. Laser pulse propagates normally to the wire, and along the strong gradient of applied static magnetic field. We simulate numerically plasma plume formation and directional expansion with emphasis on lasermatter energy coupling and momentum production. [1] A. Batishcheva, O. Batishchev, J.L.Cambier, Laser Ablation with applied magnetic field for electric propulsion, Bulletin APS, \textbf{57} (12) 329, 54th APS DPP, Providence, Oct 29  Nov 2, 2012. [Preview Abstract] 

C1.00288: Continued study and modeling of compact, RFdriven plasma source Alexander Hyde, Richard Kamieneski, Andrew Taylor, Oleg Batishchev We will be reporting on the theoretical studies and further development of a compact RFdriven gas discharge plasma source [1] operating at a wide range of pressures. Positive results have been obtained using a variety of mono and diatomic atmospheric gases, including helium and nitrogen. Successful source operation has also been achieved with magnetic field arrangements utilizing chassis of permanent rareearth magnets. The results of more sophisticated experimental investigations will be discussed, along with associated theoretical studies and numerical modeling of source operation and plasma dynamics. [1]~A.Hyde, R.Kamieneski, O.Batishchev, Development of a compact atmospheric pressure plasma source, Bulletin APS, \textbf{57} (12) 324, 54th APS DPP, Providence, Oct 29  Nov 2, 2012. [Preview Abstract] 

C1.00289: Comparison of antennae designs for RF plasma source Richard Kamieneski, Alexander Hyde, Andrew Taylor, Oleg Batishchev We study different antennae designs for inductivelycoupled discharges to optimize RFplasma coupling at 13.56MHz and minimize heat losses. In particular, we examine ways to optimize surface density for current conductors and minimize ohmic heating by using silver alloys. Results of numerical and experimental investigation of both rigid and flexible antenna designs are discussed. [Preview Abstract] 

C1.00290: CollisionalRadiative modeling of plasma UVVIS emission spectra Andrew Taylor, Alexander Hyde, Richard Kamieneski, Oleg Batishchev Numerical collisionalradiative (CR) models can theoretically derive the temperature and excited state population densities of interstellar and experimental plasmas. Noninvasive photoemission spectroscopy is an invaluable diagnostic technique to verify CR model predictions. $He, Ar,$ and $N_{2}$ plasmas are created in vacuum tube, and emission is collected from 5mtorr to 20torr gas pressures. Effects of pressure on spectrum and population densities will be shown. We will discuss the CR modeling of various conditions and compare these simulations to the collected spectra. [Preview Abstract] 

C1.00291: Exploiting Low Separation Rank Structures in ManyBody Methods Scott Thornton With the rapid advancement of highperformance computing capabilities, electronic structure calculations of large, complex, realistic molecules are now feasible with HartreeFock (HF) and density functional theory (DFT). However, due to their inherent inability to capture the necessary electron correlation effects, it is sometimes necessary to go beyond the singleparticle picture of HF and DFT. One technique for going beyond DFT is that of the GW method. The GW method includes screening effects at the random phase approximation (RPA) level. The implementation of the GW method can be cumbersome due to the fact that all of the functions involved are six dimensional. One approach to numerical computing in higher dimensional spaces is to discover and exploit low separation rank structure in physical quantities. We will discuss techniques that advance beyond those currently discussed in the literature seeking a unified framework that provides rigorous error control and greater computational efficiencies. [Preview Abstract] 

C1.00292: POSTDEADLINE 

C1.00293: Effect of Conformation in Charge Transport for Semiflexible Polymers Rodrigo Noriega, Alberto Salleo, Andrew Spakowitz Current models for the electronic properties of semiconducting conjugated polymers do not include the hierarchical connectivity between charge transport units that results from the physical makeup of the materials. Concepts like onchain vs. interchain mobility anisotropy have been known for a long time, yet they must be artificially incorporated into simulations. Models that achieve remarkable predictive power but provide limited physical insight when applied to this new class of materials are of limited use for the rational design of new conjugated polymers. Here we present a new model in which the morphology of individual polymer chains is determined by wellknown statistical models and the electronic coupling between units is described using Marcus theory. Combining knowledge from polymer physics and semiconducting materials into an analytical and computational model that realistically incorporates the structural and electronic properties of conjugated polymers, it is possible to explain observations that previously relied on phenomenological models. The multiscale behavior of charges in these materials (high mobility at short scales, low mobility at long scales) can be naturally described with our framework. [Preview Abstract] 

C1.00294: Towards Ultracold Mixtures of Lithium and Cesium Asaf ParisMandoki, Jonathan Nute, Matt Jones, Raghavan Kollengode Easwaran, Sonali Warriar, Lucia Hackermueller Ultracold mixtures hold the promise of understanding new phases of matter and collisions at very low energies. We are setting up an experiment for bosefermi mixtures of ${}^6$Li and ${}^{133}$Cs, which are especially well suited to study impurities, transport, solitons or mixtures in optical lattices. Here we present the current status of our experiment. We detail the cooling schemes for the two atom species and include the recent development of implementing evaporative cooling to produce a molecular BEC of ${}^6$Li. We discuss our contribution to the Quantum Integrated Light and Matter Interface European collaboration (QuILMI) about coupling cesium atoms to waveguides in a testchip. [Preview Abstract] 

C1.00295: Surface passivation studies of CdTe single crystals and polycrystalline films Matthew Reese, Craig Perkins, Joseph Luther, Teresa Barnes, Wyatt Metzger Cadmium telluridebased photovoltaics have seen an impressive level of commercial growth due to their low manufacturing cost in spite of their low voltages. Typically, open circuit voltages peak at approximately 850 mV for this 1.5 eV bandgap material system. A large amount still needs to be understood about the various bulk and surface recombination mechanisms before these energetic losses can be significantly reduced. This work focuses on characterizing and understanding surface effects in both single crystals and polycrystalline films with lifetimes as measured by timeresolved photoluminescence (TRPL) and xray photoemission spectroscopy (XPS). Typically, tau$_{\mathrm{1}}$ lifetimes of untreated and undoped CdTe material are 100 ps or less. These short lifetimes indicate very high surface recombination velocities exceeding 100,000 cm/s. We will share results on various wet and dry surface treatments that can improve this undoped material's lifetime, some by an order of magnitude, as well as give some preliminary indications as to the mechanism of their surface passivation. [Preview Abstract] 

C1.00296: Thermodynamics of the $\alpha$$\gamma$ cerium phase transition from first principles Jordan Bieder, Amadon Bernard The Dynamical Mean Field Theory (DMFT) combined with density functional theory in the local approximation has successfully described with a good accuracy strongly correlated materials. Thus, in this work, we focused on the $\alpha\rightleftharpoons\gamma$ cerium isostructural phase transition. However, in order to be predictive on ground state properties, a good accuracy must be obtained from the DFT and the DMFT side. For this purpose we use our selfconsistent DFT+DMFT scheme in the PAW framework with our new implementation of the strong coupling ContinuousTime Quantum Monte Carlo (CTQMC) solver to treat the impurity problem inside the DMFT. We start showing the need of charge selfconsistency to study the ground state properties of cerium. Afterwards, we show the existence of two inflection points on the internal energy curves that disappear at very low temperature. Moreover, we compute the free energy to investigate the phase transition. Our DFT+DMFT scheme does not reproduce the phase transition but we do observe a softening of the bulk modulus which is a signature of the transition. Lastly, the inclusion of spinorbit coupling is discussed. It is interpreted as a temperature renormalization. Indeed, our entropic stabilization at 800K is coherent with experiment at 400K. [Preview Abstract] 

C1.00297: Proceedings on Exploring the Miniature Dilatometer Based upon AFM Piezocantilever Liran Wang, David Graf, JuHyun Park, Timothy Murphy, Stanley Tozer, Eric Palm, George Schmiedeshoff, John Sarrao, Jason Cooley We report on the improved design of a miniature AFM cantilever based dilatometer. Compared to the traditional capacitance dilatometer and fiber bragg grating (FBG) dilatometers, this dilatometer has unique merits. This dilatometer has the ability to measure very small samples with lengths at submm levels, low temperature and field dependence, is compact to allow for rotation, and works well irrespective of being in a changing liquid or gas environment (i.e. within a flow cryostat or mixing chamber). Moreover, this technique shows suitability for application in oscillatory magnetostricton measurements. The final advantage of it is shown by successful simultaneous multiaxis dilation measurements, which are considered to be a challenge for the other dilatometer techniques. To illustrate the capabilities of this dilatometer, the low temperature thermal expansion and magnetostriction measurements on the heavy fermion superconductor CeCoIn$_{5}$ and its analog LaRhIn$_{5}$ will be presented. Measurements on CeCoIn$_{5}$ were made at various temperatures as well as rotating in field allowing a complete 3Dphase diagram to be constructed. In addition, angledependent quantum oscillations in LaRhIn$_{5}$ at $\sim$ 25 mK were successfully observed. [Preview Abstract] 

C1.00298: Landau Diamagnetism in Graphene Fengxin Chen, Bo Tian, Yong Zhang, Hong Zhao, Weiwei Cai On the basis of the $\pi $ electrons, which are free to move from carbon atom to adjacent carbon atom under the influence of impressed fields, graphene suspected has a properties of Landau diamagnetism discovered in 1930. Starting from colloidal graphene, we report an experiment of alignment of large quantity monolayer and fewlayer graphene in a solution by magnetic field, due to the significant high diamagnetism and the anisotropy in graphene. By this method, an novel material in anisotropic optical transmittance was demonstrated. [Preview Abstract] 

C1.00299: Precious metalfree catalyst for purification of automotive exhausts: NO dissociation on Cu oxide surfaces Kuniyuki Miwa, Hideaki Kasai, Allan Abraham Padama, Joaquin Lorenzo Moreno The dissociation of NO$_{\mathrm{x}}$ molecule on catalysts is the ratelimiting step for its reduction process and is the subject of recent investigations related to exhaust gas purification. Threeway catalysts which are composed of Rh, Pd and Pt, are known to work well for such purpose; however, their expensive cost hinders their applicability. In this work, Computational Materials Design based on density functional theory was employed to test the efficiency of Cubased catalysts for NO dissociation. It was found that the dissociation path of NO on Cuterminated Cu$_{2}$O(111) and CuO(110) surfaces is comparable with Rh(111). This is attributed to the modified electronic structure of the surface Cu atoms of Cu oxides in comparison with Cu(111). The calculated NO dissociation barriers are lower and the binding energies of coadsorbed N and O atoms are weaker on Cu oxides than on Rh(111), which is favorable for subsequent reactions. Our experimental collaborator had also verified that Cu oxides can be better catalysts than Rh, Pd and Pt for the purification of exhaust gases. The details of this work and the oxidation of CO in the presence of dissociated NO will be discussed in the meeting. [Preview Abstract] 

C1.00300: Linking Researchers with their Research: Persistent identifiers, registries, and interoperability standards Laurel Haak, Rebecca Bryant While in some scientific disciplines researcher identification and data citation is an established community norm, lack of interoperability between identification systems for research works on the one hand and ambiguity of contributor names on the other remains a major hurdle. Improving the ease by which researchers are uniquely and unambiguously associated with their research contributions across systems and disciplines can support citability and in turn provide incentives to share works and datasets. This in turn can facilitate information flow and enable data reuse. In this presentation, we will illustrate the potential of coordinating persistent identifier initiatives across einfrastructures using \textbf{ORCID} and the \textbf{ODIN Project}. ORCID is a communitydriven organization that provides a registry of unique and persistent identifiers for researchers. The ORCID registry connects together existing but fragmented researcher identifiers, and stores persistent connections to publications, datasets, grants, and current and past affiliations. ODINthe ORCID and DataCite Interoperability Frameworkis a twoyear EC project with the goal of connecting existing identifiers across multiple services and infrastructures. Together, these two efforts have supported improvements in the way author and contributor information is collected for publications and datasets that go a long way to addressing name ambiguity and citability problems in research communication. [Preview Abstract] 

C1.00301: ABSTRACT WITHDRAWN 

C1.00302: Fast Lattice Monte Carlo Simulations of Polymers Qiang Wang, Pengfei Zhang The recently proposed fast lattice Monte Carlo (FLMC) simulations (with multiple occupancy of lattice sites (MOLS) and Kronecker $\delta$function interactions) give much faster/better sampling of configuration space than both offlattice molecular simulations (with pairpotential calculations) and conventional lattice Monte Carlo simulations (with self and mutualavoiding walk and nearestneighbor interactions) of polymers.\footnote{Q. Wang, \textbf{Soft Matter 5}, 4564 (2009); \textbf{6}, 6206 (2010). } Quantitative coarsegraining of polymeric systems can also be performed using lattice models with MOLS.\footnote{P. Zhang and Q. Wang, \textbf{Soft Matter 9}, 11183 (2013).} Here we use several model systems, including polymer melts, solutions, blends, as well as confined and/or grafted polymers, to demonstrate the great advantages of FLMC simulations in the study of equilibrium properties of polymers. [Preview Abstract] 

C1.00303: Formation of hBN monolayers by nitridation of ZrB$_{2}$ thin films with epitaxial silicene Kohei Aoyagi, Antoine Fleurence, Rainer Friedlein, Yukiko YamadaTakamura Among the twodimensional materials that recently received increased attention are atomically thin honeycomb layers called silicene and hexagonal boron nitride (hBN) monolayers. The combination of both types of layers may allow for either the electrical insulation of silicene from metallic substrates or the protection of silicene from atmospheric conditions, as required for the use of silicene in any electronic device application. In this study is reported the formation of hBN monolayers by nitridation of ZrB$_{2}$ thin films grown on Si(111) substrates, which have epitaxial silicene on the surface.\footnote{A. Fleurence, \textit{et al.}, Phys. Rev. Lett. 108, 245501 (2012).} As revealed by XPS, following the formation of silicon nitride by treatment of the surface with an rf nitrogen plasma, nitrogen atoms released from the silicon nitride layer react with B atoms released from ZrB$_{2}$ upon annealing under ultrahigh vacuum conditions to form a hBN monolayer in direct contact and in an epitaxial relation with the diboride. As such, the ratio of 5 unit cells of hBN to 4 unit cells of ZrB$_{2}$ is found to cause a distinct moir\'{e} pattern observed by STM. The electronic structure of the surface is dominated by an intense and welldefined BN $\pi $band as expected for highquality hBN sheets covering large areas of the surface. [Preview Abstract] 

C1.00304: Oscillations in a LandauZener Transition Guozhu Sun, Xueda Wen, Jian Chen, Lin Kang, Peiheng Wu, Siyuan Han LandauZener transition has been explored in varieties of systems and becoming more and more applicable especially in the developing quantum information processing. But the effects of finite sweeping range in the vicinity of an avoided energylevel crossing is lack of experimental evidence. Here we experimentally proved the inapplicability of the LandauZener formula in the vicinity of an avoided energylevel crossing and demonstrated two anomalous oscillations in the LandauZener transition, which agree well with the numerical simulations. Our results not only provide a closer view of LandauZener transition but also shed light on its application in the quantum state manipulation. [Preview Abstract] 

C1.00305: Dirac Fermions in heterostructures for designer topological phases Ji Feng Massless Dirac Fermions are found in graphene and on the surfaces of topological insulators, which are quasiparticles moving at a constant speed independent of its energy as governed by relativistic quantum mechanics. In this talk, I will show, via interfacial orbital design of Dirac states, emergent topological phases can be engineered in artificial heterostructures. As a first example, I will show that a novel class of half semimetallic Dirac electronic phase emerges at the interface CrO$_2$ with TiO$_2$ in both thin film and superlattice configurations. With four spinpolarized Dirac points in the band structure, this system with simple, nontopological oxides displays spontaneous quantum anomalous Hall effect. In a second example, I will show that the superlattice valley engineering, starting with the SnTe topological mirror insulator, leads to designer topological phases with a remarkably rich phase diagram. [Preview Abstract] 

C1.00306: Superconducting gap symmetry evolution in a model of correlated fermions Irina Bariakhtar, Alex Nazarenko We investigate the evolution of the symmetry of the energy gap in the spectrum of the superconducting quasiparticles as a function of the density of carriers in a strongly correlated 2D fermionic model. Considered are several different types of 2D lattices, including square and triangle. In the latter case we find strong indication of the triplet pair formation in the isotropic case near halffilling. In the case of the square lattice the higher densities away from halffilling favor the singlet extended swave symmetry, which eventually becomes dominant. We also show that gradual inclusion of the 3rd dimension produces the same effect even near halffilling. We relate our results to the existing phenomenological models. Also we provide the implications of the found behavior on experimental measurements. [Preview Abstract] 

C1.00307: FirstPrinciples Investigation of Vibrational Properties of CaTiO$_{ 3}$ Crystal Subenia Medeiros, Maeva Araujo The structural, electronic, vibrational, and optical properties of perovskite CaTiO$_{3}$ in the cubic, orthorhombic, and tetragonal phase are calculated in the framework of density functional theory (DFT) with different exchangecorrelation potentials by CASTEP package. The calculated band structure shows an indirect band gap of 1.88 eV at the $\Gamma $\textbf{R} points in the Brillouin zone to the cubic structure, a direct band gap of 2.41 eV at the $\Gamma $\textbf{  }$\Gamma $ points to the orthorhombic structure, and an indirect band gap of 2.31 eV at the\textbf{ M  }$\Gamma $ points to the tetragonal phase. I have concluded that the bonding between Ca and TiO$_{2}$ is mainly ionic and that the TiO$_{2}$ entities bond covalently. Unlike some perovskites the CaTiO$_{3}$ does not exhibit a ferroelectric phase transition down to 4.2 K. It is still known that the CaTiO$_{3}$ has a static dielectric constant that extrapolates to a value greater than 300 at zero temperature, and the dielectric response is dominated by low frequency ($\nu \approx $ 90cm$^{1})$ polar optical modes in which cation motion opposes oxygen motion. Our calculated lattice parameters, elastic constants, optical properties, and vibrational frequencies are found to be in good agreement with the available theoretical and experimental values. The results for the effective mass in the electron and hole carriers are also presented in this work. [Preview Abstract] 

C1.00308: 3D simulation of triple gate tunnel field effect transistor for enhanced transconductance and low subthreshold swing Nurunnahar Islam Mou, Massood TabibAzar Tunnel field effect transistors (TFET) are among emerging candidates with good subthreshold swing (SS) much lower than the thermal limit of 60 mV/dec. TFET is a gated P$^{+}$IN$^{+}$ diode operated in reverse bias mode to use bandtoband tunneling as the working principle. However, low oncurrent and dependence of SS on gate voltage remain problematic prohibiting practical application of TFETs. Optimized device performance depends on many factors such as device geometry, gate geometry, choice of gate oxide and source region material, doping concentration etc. [1]. We present a 3D simulation study of a triple gate all silicon TFET structure and evaluate the performance of the device for enhanced transconductance. In the simulated device, the gate wraps the channel region from three sides and hence the name triple gate. SS was optimized as functions of source and drain doping concentration, device thickness, width as well as different source and channel material system. Gate length scaling is also explored to enable further insight into affects of scaling on the device performance.\\[4pt] [1] Ionescu, A. M. {\&}~Riel, H. Tunnel fieldeffect transistors as energyefficient electronic switches. \textit{Nature }\textbf{479}, 329337 (2011) [Preview Abstract] 

C1.00309: Using gold nanorods and nanoshells in photothermal cancer therapy Tran Nhung, Vu Duong, Dustin Tracy, David Drosdoff, Lilia Woods, Huong Nguyen, Do Nga, N.A. Viet, Anh Phan The ability of strongly absorbing nearinfrared radiation and efficiently scattering photon energy of gold nanoshells and nanorods has been investigated for cancer treatments. The nanostructures sizes are chosen to achieve a surface plasmon resonance localized peak in the ``humanbeing skin windows'' (650900 nm), which is the best possible regime of operation for cancer treatment. After injecting nanoshell and nanorod solutions into chicken tissues, variations of temperature of samples as a function of time with and without nearinfraredlight irradiation at 808 nm are reported. The temperature of chicken tissues injected with nanorods is found to be greater than that of the samples with nanoshells for the same absorbance of nanomaterials. The photothermal transduction efficiency of nanorods is also proved to be higher than that of nanoshells. Our theoretical calculations show excellent agreement with the experimental data. [Preview Abstract] 

C1.00310: Inhomogeneous Topological Superfluidity in OneDimensional SpinOrbitCoupled Fermi Gases Chun Chen We theoretically predict an exotic topological superfluid state with a spatially modulated pairing gap in onedimensional spinorbitcoupled Fermi gases. This inhomogeneous topological superfluidity is induced by applying simultaneously a perpendicular Zeeman magnetic field and an equally weighted Rashba and Dresselhaus spinorbit coupling in onedimensional optical lattices. Based on the selfconsistent Bogoliubovde Gennes theory, we confirm that this novel topological phase is a unique condensation of Cooper pairs, which manifests the interplay between the inhomogeneity of a superfluid and its nontrivial topological structure. The properties of the emergent Majorana bound states are investigated in detail by examining the associated ${Z}_{2}$ topological number, the eigenenergy and density of states spectra, as well as the wave functions of the localized Majorana end modes. The experimental feasibility of observing this new topological state of matter is also discussed. [Preview Abstract] 

C1.00311: Total Ionizing Dose (TID) Effects of $\gamma $ Ray Radiation on Ag/AlO$_{\mathrm{x}}$/Pt Resistive Switching Memory Fang Yuan, Zhigang Zhang, Shanshan Shen, Liyang Pan, Jun Xu The TID effects of $\gamma $ rays generated from a $^{\mathrm{60}}$Co source on the Ag/AlO$_{\mathrm{x}}$/Pt resistive switching (RS) memory is studied. Memory performances, including initial resistance state (IRS), low/high resistance state (LRS/HRS), forming voltage (V$_{\mathrm{f}})$, switching voltage (V$_{\mathrm{set}}$/V$_{\mathrm{reset}})$ and retention reliability are examined on the memory devices before and after exposure to 1M rad (Si) radiation. The LRS is robust to the radiation whereas a little degeneration of uniformity is found in IRS and HRS, which is caused by the radiation induced defects (mainly holes), trapped in the oxide. For the same reason, V$_{\mathrm{f}}$ increases several multiples after radiation. However surprisingly, both V$_{\mathrm{set}}$ and V$_{\mathrm{reset}}$ decrease during the RS and the retention performance is greatly improved. Based on these TID effects, it is proposed that the RS mechanism in Ag/AlO$_{\mathrm{x}}$/Pt, Ag conducting filament based switching, may be reinforced through $\gamma $ radiation, which assists in stabilizing the growth/rupture of Ag filaments. The high radiation tolerance of AlO$_{\mathrm{x}}$based RS memory devices suggests a potential for aerospace and nuclear applications. [Preview Abstract] 

C1.00312: A study on Bidispersed Magneto rheological fluids using Magnetite and Cobalt Ferrite nanoparicles in FeNi Alloy Rajini Kanth Bhogoju, Venkateswarlu Manda Magneto rheological (MR) fluids are a class of smart materials which exhibits fast, reversible and tunable transition from a free flowing state (liquid) to semisolid state on the application of an external magnetic field in a few milliseconds. They offer an outstanding capability of active control of mechanical properties, because they provide a simple and fast response interface between electronic control and mechanical devices/systems. Generally these MR fluids contain micron size magnetically soft particles (Fe, Co) dispersed in a nonmagnetic carrier fluid. Here an attempt is made to make the MR fluids with the FeNi based alloys and the nano particulate magnetite and Cobalt ferrite(bidispersed) mixed to enhance the yield stress and reduce the particle settling rate. Nanosized Magnetite and Cobalt ferrite particles were synthesized using simple wet chemical method. There is a measurable predictable variation of rheological properties on the wt{\%} of the nanometer sized particles is increased relative to the wt{\%} of the micron sized particles, while maintaining a constant solids loading in the MR fluids samples. As the field is pickingup, we undertake present study. [Preview Abstract] 

C1.00313: Measure synchronization in quantum manybody systems Haibo Qiu, Bruno JuliaDiaz, Miguel Angel GarciaMarch, Artur Polls The concept of measure synchronization between two coupled quantum manybody systems is presented. In general terms we consider two quantum manybody systems whose dynamics gets coupled through the contact particleparticle interaction. This coupling is shown to produce measure synchronization, a generalization of synchrony to a large class of systems which takes place in absence of dissipation. We find that in quantum measure synchronization, the manybody quantum properties for the two subsystems, e.g. condensed fractions and particle fluctuations, behave in a coordinated way. To illustrate the concept we consider a simple case of two species of bosons occupying two distinct quantum states. Measure synchronization can be readily explored with stateoftheart techniques in ultracold atomic gases and, if properly controlled, be employed to share quantum correlations between different degrees of freedom. [Preview Abstract] 

C1.00314: ABSTRACT MOVED TO P1.00098 

C1.00315: Critical Temperature and Field of a LongRange Maximally Even Antiferromagnetic Ising Model in the Mean Field Approximation Richard Krantz A longranged, onedimensional, antiferromagnetic Ising model on a twosublattice Maximally Even (ME) lattice has been developed in the Mean Field Approximation (MFA). A distribution of sites on a onedimensional lattice, a socalled Maximally Even (ME) Distribution, can be used to describe unusual magnetic orderings of antiferromagnetic Ising systems. In the limit of zero applied magnetic field the temperature at which the net magnetization of the lattice goes to zero, the socalled critical temperature, can be evaluated. When the magnetization of the ``down'' lattice approaches zero the lattice makes a transition to the paramagnetic state. The magnetic field at which this occurs is the critical field. Both the critical field and the critical temperature depend on: 1) the structure of the lattice  the distribution of up and down lattice sites, 2) the number of neighboring interactions accounted for, and 3) the strength of the interaction between neighboring spins. [Preview Abstract] 

C1.00316: Exact analysis of a Veselago lens in the quasistatic regime Asaf Farhi, David J. Bergman The resolution of conventional optical lenses is limited by the wavelength. Materials with negative refractive index have been shown to enable the generation of an enhanced resolution image where both propagating and nonpropagating waves are employed. We analyze such a Veselago lens by exploiting some exact one dimensional integral expressions for the quasistatic electric potential of a point charge in that system. Those were recently obtained by expanding that potential in the quasistatic eigenfunctions of a threeflatslabs composite structure. Numerical evaluations of those integrals, using realistic values for physical parameters like the electric permittivities of the constituent slabs and their thicknesses, reveal some surprising effects: E.g., the maximum concentration of electric field occurs not at the geometric optics foci but at the interfaces between the negative permittivity slab and the positive permittivity slabs. The analysis provides simple computational guides for designing such structures in order to achieve enhanced resolution of an optical image. [Preview Abstract] 

C1.00317: Spray Pyrolysis of Nonstoichiometric Zinc Tungstate Thin Films Seth King, Brandon Zink, Ethan Dinauer, Joseph Krueger Zinc tungstate (ZnWO$_{\mathrm{4}})$ has recently shown promise as a photon harvesting material for possible applications in photovoltaic and photocatalytic devices. While substantial work has focused on understanding the properties of stoichiometric ZnWO$_{\mathrm{4}}$, little work has investigated the nonstoichiometric material where the Zn to W ratio is varied from ideal. In the present study, we report on the fabrication of nonstoichiometric zinc tungstate thin films by spray pyrolysis. Results suggest that this technique may be utilized to deposit material with any desired Zn to W ratio. Therefore, the structural, electrical, and optical properties of nonstoichiometric zinc tungstate materials may be characterized and engineered for specific applications. [Preview Abstract] 

C1.00318: Bichromatic Resonant LightScattering From a Quantum Dot Manoj Peiris, Kumarasiri Konthasinghe, Ying Yu, Zhichuan Niu, Andreas Muller The nearresonant response of a twostate quantum system to a nearresonant driving field constitutes a central problem of quantum optics. Best known is the case of monochromatic laser excitation for which the scattered light distinctively exhibits oscillations at the Rabi frequency. In contrast, nonmonochromatic driving fields, although inherent to all pumpprobe experiments, have been applied little under resonant detection, despite obvious relevance for advanced coherent manipulation. For example resonant light scattering under bichromatic laser excitation has been theoretically studied spectrally, and measured using atomic beams. We report on the spectral and temporal properties of the light scattered nearresonantly by a single quantum dot under bichromatic laser excitation. The dynamics of the observables are characterized by Rabi oscillations but also oscillations at half the difference of the lasers' frequencies and harmonics thereof, persisting beyond the natural lifetime. Such ``dressing'' of the optically ``dressed'' states is a significant step towards complete quantum control of a quantum bit. [Preview Abstract] 

C1.00319: MetalOrganic Coordination Number Determined Charge Transfer Magnitude HungHsiang Yang, YuHsun Chu, ChunI Lu, TsungHan Yang, KaiJheng Yang, ChaoCheng Kaun, Germar Hoffmann, MinnTsong Lin By the appropriate choice of head groups and molecular ligands, various metalorganic coordination geometries can be engineered. Such metalorganic structures provide different chemical environments for molecules and give us templates to study the charge redistribution within the metalorganic interface. We created various metalorganic bonding environment by growing selfassembly nanostructures of FePTCDA (3,4,9,10perylene tetracarboxylic dianhydride) chains and networks on a Au(111) surface. Bonding environment dependent frontier molecular orbital energies are acquired by low temperature scanning tunneling microscopy and scanning tunneling spectroscopy. By comparing the frontier energies with the molecular coordination environments, we conclude that the specific coordination affects the magnitude of charge transfer onto each PTCDA in the FePTCDA hybridization system. [Preview Abstract] 

C1.00320: Evaluation of spin orbit interactions in InAs quantum well structure using electrical method Joonyeon Chang, Youn Ho Park, Hyungjun Kim, Suk Hee Han, Jonghwa Eom, HeonJin Choi, Hyun Cheol Koo Spinorbit interactions are very interesting phenomena in solid state physics because they provide a way that an electric field can control spin information. In a twodimensional system, the Rashba field arising from structural inversion asymmetry can be modulated by applying an external gate voltage. The Dresselhaus field which results from bulk inversion asymmetry is relatively difficult to detect in a quantum well structure. Both Rashba and Dresselhaus effects have been actively investigated. However, they are phenomenologically inseparable so the evaluation of their individual parameters is not simple. In this study, we determined the absolute value of the Rashba and Dresselhaus parameters separately for an InAsbased quantum well layer via an electrical method. The Rashba spinorbit interaction effective field is always in the plane of the twodimensional electron gas and perpendicular to the carrier wavevector but the direction of the Dresselhaus field depends on the crystal orientation. These two spinorbit interaction parameters can be determined separately by measuring and analyzing the Shubnikovde Haas oscillations for various crystal directions. In the InAs quantum well system investigated, the Dresselhaus term is just 5{\%} of the Rashba term. The gate dependence of the oscillation patterns clearly shows that only the Rashba term is modulated by an external electric field. [Preview Abstract] 

C1.00321: Energy loss behavior of photogenerated multicomponent carriers in GaN KyungSoo Yi, Hye Jung Kim, Dokyun Kim Temporal behavior and manybody effect on the energy losses of photogenerated electronhole plasma in GaN are examined in terms of various carrierphonon couplings. We report a comprehensive cooling behavior as a function of effective carrier temperature over the temperature range of 10 1500 K for carrierphonon couplings via polar and nonpolar optical phonons and piezoelectric and acoustic deformationpotentials. The manybody effect on the multicomponent carrier polarizations and phonon spectral function and effect of energy reabsorption via hot phonons are included by employing temperaturedependent dynamic responses in the rpa. We show that, as the carrier temperature decreases, the energy losses via carrieroptical phonon couplings diminish rapidly and the carrier energy relaxation is dominated through the acoustic phonon scattering at low carrier energy. From the energy loss rates, energy cooling curves are obtained as a function of time, and our result shows an initial gentle energy relaxation followed by fast relaxation. Spectral analysis of the dielectric response functions and energy loss rates are also performed and their dynamic and nonlocal behavior will be discussed. [Preview Abstract] 

C1.00322: The nature of magnetic phenomena is the electric phenomenon Yongquan Han The nature of magnetic phenomena is the electric phenomenon, that is the result of the negative and positive charge of the regular ``matrix,'' also a positive, negative charge spread by the form of the ``matrix,'' but also can be said to be the waves of electric current (the current spread by the form of wave but only transfer form, the form is not move with wave), its characteristics are: magnetic field plane and the current plane is perpendicular to each other (make up the current wave), inside the material, it performance the current wave (electric field \textless  \textgreater, magnetic field). Sent to outer space it become an electromagnetic wave, an electromagnetic wave particle (positive, negative particle move in a circle)is the smallest needle, it is unified with Maxwell electromagnetic theory, magnetic monopoles do not exist. The mechanism of information between cable transmission and wireless transmission is the same. [Preview Abstract] 

C1.00323: Frequencyshifted feedback amplifier for broadband laser cooling Michael Lim, Alexander Van Kooy, Michael Yanakas We have developed a compact, allsolid state laser amplifier for generating asymmetric sidebands with controlled number and spacing of optical frequencies. The gain element is a tapered semiconductor amplifier, used in conjunction with an acoustooptic modulator that generates reddetuned feedback frequencies. This results in asymmetric sidebands that are all lower in optical frequency than the narrowband seed laser frequency. The output laser spectrum has a welldefined edge (the input laser frequency) and multiple sidebands whose number, frequency spacing, and power are fully controlled by the seed laser characteristics and a single radio frequency input. The number of sidebands can be varied in a controlled way, and the output optical power is variable up to the Watt level of the amplifier chip. The system will be used for broadband laser cooling. [Preview Abstract] 

C1.00324: CO2 Absorption Spectroscopy and Climate Change Daniel Feldman, Eli Mlawer, Martin Mlynczak, Jon Gero, William Collins, Margaret Torn Most of the absorption, and therefore radiative forcing, due to increased atmospheric CO2 occurs in line wings, so utilizing an accurate line shape is necessary for climate science. Recent advances in CO2 absorption spectroscopy have been incorporated into benchmark linebyline radiative transfer models. These updates include the Energy Corrected Sudden Approximation to represent isolated line profiles, line mixing, and line clusters. The CO2 line profiles are subLorentzian and are explicitly modeled up to 25 cm1 from each line's center. Consistent continuum absorption is implemented over the remainder of the profile except for modest empirical adjustments based on observations. Thus, linebyline models calculate the absorption effects of CO2 that agree with theory and measurements. This is validated with longterm spectroscopic measurements from the ARM program's AERI instrument. This spectroscopy trains computationallyefficient correlatedk methods for climate model radiative transfer, but they overpredict instantaneous radiative forcing from doubled CO2 by approximately 7{\%} in part because they have larger errors handling the impact of increased CO2 in the stratosphere than the troposphere. The implications of this can be tested with supercomputers. [Preview Abstract] 

C1.00325: On The Possible CurrentConduction Mechanisms at Low temperatures in Au/nGaAs Schottky Barrier Diodes (SBDs) Sahar Alialy, Halit Altuntas, Semsettin Altundal To determine the possible currentconduction mechanisms (CCMs) at low temperatures, Au/nGaAs SBDs with SiO2 interfacial layer were fabricated and their currentvoltage (IV) characteristics were carried under room temperatures (80300 K). The ideality factor (n) and apparent barrier height ($\Phi $bo) values were found as 5.200, 0.198 eV at 80 K and 1.256, 0.613 eV at 300 K, respectively. These results indicated that possible CCM is Thermionic Field Emission (TFE) rather than Thermionic Emission (TE) or other mechanisms. While the value of $\Phi $bo increases with increasing temperature, n$\Phi $bo decreases. The negative coefficient of $\Phi $bo and BH (0K) values were found as 13x104 eV/K and 1.12 eV, respectively. This 13x104 eV/K value is close to negative temperature coefficient bandgap of GaAs (5.405x104 eV/K). On the other hand, the high value of n especially at low temperatures cannot be also explained only by TFE theory. Such behavior of n and $\Phi $bo with temperature was explained on the basis of single Gaussian distribution (GD) of the BHs. As a result to avoid these nonideal behavior of forward bias IV characteristics, the fabrication process should be carried out in very clear room at high vacuum, annealing of the samples, and use to a thin interfacial with high dielectric constant. [Preview Abstract] 

C1.00326: Molecular Detection and Phonon Filtering in HeatTransfer Spectroscopy Kamil Walczak, Kirk Yerkes We examine heat transport carried by acoustic phonons in the systems composed of nanoscale chains of masses coupled to two thermal baths of different temperatures. Thermal conductance is obtained by using linearized Landauer formula for heat flux with phonon transmission probability calculated within atomistic Green's functions (AGF) method. AGF formalism is extended onto dissipative chains of masses with harmonic coupling beyond nearestneighbor approximation, while atomistic description of heat reservoirs is also included into computational scheme. The resonant structure of phonon transmission spectrum is analyzed with respect to reservoirdimensionality effects, molecular damping, and masstomass harmonic coupling. Analysis of transmission zeros (antiresonances) and their accompanied Fanoshape resonances are discussed as a result of interference effects between different vibrational modes. Specifically, we show that the heattransferbased characterization method may be used to identify individual molecules or filter out specific phonon modes from the whole frequency spectrum. [Preview Abstract] 

C1.00327: Low subthreshod swing tunnel fieldeffect transistor with two gated intrinsic regions Yuying Zhang, Massood TabibAzar We demonstrate a novel silicon tunnel fieldeffecttransistor (TFET), based on a reversebiased p$+$pnn$+$ structure, instead of the conventional pin structure. The device was built on an ultrathin silicon body, SiO$_{2}$ and HfO$_{2}$ were used as gate dielectric. When positive gate voltage was applied to the n region, and negative gate voltage was applied to the p region, carriers accumulated at the surface of these two regions. Thus, the barrier width between them was reduced, and the conduction band of the n region became lower than the valence band of the p region. When the p$+$ region (source) was grounded and positive voltage was applied to the n$+$ region (drain), bandtoband tunneling (BTBT) took place at the pn junction. 2D device simulations were performed by using Sentaurus Device. For the devices with SiO$_{2}$ gate dielectric, when V$_{DS}=$0.1 V, the subthreshold swing was 20 mV/decade. In this case, the subthreshold swing would increase with larger V$_{DS}$. The devices with HfO$_{2}$ gate dielectric had a subthreshold swing as low as 9.58 mV/decade, when V$_{DS}$ was between 0.1 V and 0.5 V. Therefore, this silicon TFET with two gated intrinsic regions is a promising candidate for low power applications and fast switching. [Preview Abstract] 

C1.00328: Preservation of quantum correlation between separated nitrogenvacancy centers embedded in photoniccrystal cavities Wanli Yang, JunHong An, Chengjie Zhang, Mang Feng, C.H. Oh We investigate the nonMarkovian dynamics of quantum correlation between two initially entangled nitrogenvacancy centers (NVC) embedded in photonic crystal cavities (PCC). We find that a finite quantum correlation is preserved even asymptotically when the transition frequency ofthe NVC is within the band gap of the PCC, which is quantitatively different from the result of approaching zero under the BornMarkovian approximation. In addition, once the transition frequency of NVC is far beyond the bad gap of the PCC, the quantum correlation initially prepared in NVC will be fully transferred to the reservoirs in the longtime limit. Our result reveals that the interplay between the nonMarkovian effect of the structured reservoirs and the existence of emitterfield bound state plays an essential role in such quantum correlation preservation. This feature may open new perspectives for devising active decoherenceimmune solidstate optical devices. [Preview Abstract] 

C1.00329: Unconventional Superconductivity of Alkalidoped Fullerenes Anton Potocnik, Andraz Krajnc, Peter Jeglic, Kosmas Prassides, Matthew J. Rosseinsky, Denis Arcon The superconductivity of the alkalidoped fullerenes ($A_3$C$_{60}$, $A$ = alkali metal) has been so far discussed within the standard theory of superconductivity developed by Bardeen, Cooper and Shrieffer (BCS), even thought, they exhibit relatively high critical temperatures (up to $T_c = 32$ K). However, after our recent highpressure measurements on Cs$_3$C$_{60}$ such description became questionable. We have shown that the superconducting phase of $A_3$C$_{60}$, in fact, borders the antiferromagnetic insulating phase (AFI), commonly observed for hightemperature superconductors like cuprates or pnictides. In addition, we also increased the maximal $T_c$ to 38 K. To investigate this peculiar superconductivity close to the border with AFI state we employed nuclear magnetic resonance technique on Cs$_{3x}$Rb$_{x}$C$_{60}$ and on Cs$_3$C$_{60}$ at various high pressures. Our results could not be correctly explained either by the standard BCS or the extended BCS that includes electronelectron repulsion interaction  the MigdalEliashberg theory. Far better agreement is obtained by the Dynamical Mean Field Theory. Due to similarity with other unconventional superconductors these results could also be relevant to other unconventional hightemperature superconductors. [Preview Abstract] 

C1.00330: Coherent Electronic Coupling in Monolayer MoSe$_{2}$ Galan Moody, Akshay Singh, Sanfeng Wu, Yanwen Wu, Nirmal Ghimire, Jiaqiang Yan, David Mandrus, Xiaodong Xu, Xiaoqin Li Monolayer transition metal dichalcogenides (TMDs) have emerged as an interesting class of twodimensional materials due to their unique optical properties, such as a crossover from an indirecttodirect bandgap as well as valleyspecific optical selection rules. A striking feature in the linear optical spectra of TMDs is pronounced neutral and charged excitons (trions), with significantly larger binding energies than conventional semiconductors due to reduced screening. Using ultrafast twocolor pumpprobe spectroscopy, we demonstrate that Coulomb interactions responsible for the large binding energies in monolayer MoSe$_{2}$ also lead to strong coherent coupling between excitons and trions. Signatures for coherent coupling appear as isolated crosspeaks in a 2D spectrum obtained by tuning the pump and probe wavelengths through the resonances. While incoherent population transfer may partially contribute to one of the peaks, density matrix calculations reveal that the unique peak lineshapes arise from coherent excitontrion manybody interactions, whose strength is significantly larger compared to conventional semiconductor quantum wells. Strong excitontrion coherent coupling demonstrated here makes TMDs an excellent platform for future coherent optoelectronic devices. [Preview Abstract] 

C1.00331: Gate bias stressinduced threshold voltage instability of exfoliated multilayer MoS$_{2}$ field effect transistors Kyungjune Cho, Woanseo Park, TaeYoung Kim, Takhee Lee Recently, MoS$_{2}$ has attracted great attention due to its intriguing electrical properties. MoS$_{2}$ transistors with a high on/off ratio of 10$^{8}$ have recently been demonstrated using HfO$_{2}$ as the top gate dielectric [1]. Despite the merits of MoS$_{2}$, large variations in the properties of MoS$_{2}$ FET devices due to extrinsic effects may result in limitations in device applications. Here, we investigated the gate bias stress effects of exfoliated multilayered MoS$_{2}$ FETs. We observed that when a positive gate bias stress was applied to the device, the current decreased and the threshold shifted in the positive gate bias direction and vice versa. The electrical instability of the MoS$_{2}$ FETs was influenced by the measurement conditions. These phenomena can be explained by the charge trapping due to the adsorption or desorption of oxygen and/or water on the MoS$_{2}$ surface with a positive or negative gate bias, respectively, under an ambient environment. Our study will be helpful in understanding the electricalstressinduced instability of the MoS$_{2}$based electronic devices [2]. \\[4pt] [1] B. Radisavljevic et al., Nat. Nanotechnol. 6, 147(2011).\\[0pt] [2] K. Cho et al., ACS Nano, 7, 7751(2013). [Preview Abstract] 

C1.00332: High Energy Proton Beam Irradiation Effects on MoS$_{2}$ Field Effect Transistors TaeYoung Kim, Kyungjune Cho, Woanseo Park, Takhee Lee Recently, MoS2 has gained significant attention due to its direct bandgap of 1.8 eV as a single layer. Numerous studies have explored the application of MoS2 in nanoelectronic devices [1]. High energy particle irradiation has been utilized to tailor the electrical properties of nanowire FET devices [2]. Similarly, a few experimental studies have investigated the irradiation effect of MoS2 [3]. However, a comprehensive study of high energy particle beams on MoS2 thinfilm FET devices have not yet been investigated. In this study, we investigated the effect of irradiation on MoS2 FETs with 10 MeV proton beams. The electrical characteristics of the devices were measured before and after the proton irradiation with several beam conditions. The observed changes in the electrical properties originate from protonirradiationinduced traps, including positive oxidecharge traps in the SiO2 layer and trap states at the interface between the MoS2 channel and the SiO2 layer. Our study will enhance the understanding of the influence of high energy particle irradiations on MoS2based nanoelectronic devices. \\[4pt] [1] B. Radisavljeciv et al., Nat. Nanotechnol. 6, 147 (2011).\\[0pt] [2] W.K. Hong et al., ACS Nano 4, 811 (2010).\\[0pt] [3] S. Mathew et al., Appl. Phys. Lett. 101, 102103 (2012). [Preview Abstract] 

C1.00333: Computational modeling of the Fc$\alpha $RI receptor binding in the Fc$\alpha $ domain of the human antibody IgA: Normal Modes Analysis (NMA) study Manori Jayasinghe, Monica Posgai, Sam TonddastNavaei, George Ibrahim, George Stan, Andrew Herr Fc$\alpha $RI receptor binding in the Fc$\alpha $ domain of the antibody IgA triggers immune effector responses such as phagocytosis and antibodydependent cellmediated cytotoxicity in eukaryotic cells. Fc$\alpha $ is a dimer of heavy chains of the IgA antibody and each Fc$\alpha $ heavy chain which consisted of two immunoglobulin constant domains, C$_{\mathrm{H}}$2 and C$_{\mathrm{H}}$3, can bind one Fc$\alpha $RI molecule at the C$_{\mathrm{H}}$2C$_{\mathrm{H}}$3 interface forming a 2:1 stoichiometry. Experimental evidences confirmed that Fc$\alpha $RI binding to the Fc$\alpha $ C$_{\mathrm{H}}$2C$_{\mathrm{H}}$3 junction altered the kinetics of HAA lectin binding at the distant IgA1 hinge. Our focus in this research was to understand the conformational changes and the network of residues which coordinate the receptor binding dynamics of the Fc$\alpha $ dimer complex. Structurebased elastic network modeling was used to compute normal modes of distinct Fc$\alpha $ configurations. Asymmetric and unliganded Fc$\alpha $ configurations were obtained from the high resolution crystal structure of Fc$\alpha $Fc$\alpha $RI 2:1 symmetric complex of PDB ID 1OW0. Our findings confirmed that Fc$\alpha $RI binding, either in asymmetric or symmetric complex with Fc$\alpha $, propagated longrange conformational changes across the Fc domains, potentially also impacting the distant IgA1 hinge. [Preview Abstract] 

C1.00334: Average band structure of smectic C? type random materials Juan Adrian Reyes Cervantes We consider a Smectic C? type structure which exhibits alignment fluctuations which can be described by noise associated with both director angles. We take the propagation of axially incident electromagnetic waves, and from Maxwell equations, we establish the stochastic governing set of equations corresponding to optical phenomena. We note that this set of equations can be expressed as a linear vector stochastic system of differential equations with multiplicative noise. We use a procedure to calculate from the stochastic differential set of equations, the governing equations for the expected value of the electromagnetic transverse magnetic and electric fields for a certain autocorrelation function, and calculate explicitly their corresponding band structure for a particular spectral noise density. We have shown that the average resulting electromagnetic fields exhibit a biased decaying exponential dependence which impedes to propagate the waves in one sense while it permits them in the other sense. We have also found a remarkable widening of the band gap and the appearance of new local maxima for the modes without band gap. [Preview Abstract] 

C1.00335: Assembly of a Novel Micro Dispenser for Applications in Microfluidics Harjyot Mohar, Annie O, Victor Hernandez, Arturo Estrada, Leonel Munoz, Sewan Fan, Laura Fatuzzo, Steven Jimenez Recently there has been tremendous interest in applying inkjet printing technology in diverse fields of biology, chemistry, medicine and nanotechnologies. Two popular techniques are frequently employed to make reliable atomized liquid droplets: piezo inkjet and thermal inkjet techniques. In this presentation, we describe our design and construction for a novel dropon demand (DOD) droplet dispenser using the piezo inkjet technique that is simple to construct and operate and makes use of readily available components. The droplet dispenser can be easily fitted with cost effective glass nozzles. It can be reliably tuned to produce consistent droplet sizes in the micron range. Also, we describe a camera imaging system that is constructed to measure the ejected droplet velocities. Through the terminal velocities reached by the droplets and using Stokes' law for fluid drag force, this imaging system also makes independent measurement possible for the dispensed drop diameters. [Preview Abstract] 

C1.00336: Thermodynamic Analysis for Nearfield Thermal Radiation: Energy and Entropy Transfer Yi Zheng, Arvind Narayanaswamy It can be argued that what is fundamental to Planck's theory of blackbody radiation is not the concept of the quanta but the concept of entropy of electromagnetic waves. Planck's work relies on the thermodynamic analysis of thermal radiation in a cavity, which requires knowledge of energy, entropy and momentum of photons. Planck's analysis, though, is restricted to the case when nearfield effects such as diffraction and tunneling of evanescent waves are absent. We proposed a method to evaluate the entropy density and entropy flux in vacuum between two halfspaces that takes into account nearfield effects. It is used to determine the maximum work that can be extracted through nearfield radiative transfer between two objects at different temperatures. [Preview Abstract] 

C1.00337: Cation Transport in Li$^+$ and Na$^+$ Rich Antiperovskites John Howard, Luke Daemen, Yusheng Zhao A large number of compounds possessing the perovskite crystal structure demonstrate interesting properties such as ferroelectricity, magnetoresistance, and superconductivity. In this study, we present findings on a new class of materials, namely Li$^+$ and Na$^+$ rich antiperovskites, with emphasis on cation transport for solid state battery applications. The electrolytes have the general formula $A_3BX$ where A is a Li$^+$ or Na$^+$ cation, B is an O$^{2}$ or S$^{2}$ anion, and X is a Cl$^$ or Br$^$ anion; mixed compositions were also studied. Xray diffraction techniques were used for phase identification, sample purity, and unit cell refinement. In each case, the materials crystallize in a cubic unit cell with space group $Pm\bar{3}m$. The ionic conductivity was determined for each material as a function of temperature using impedance spectroscopy methods. Activation energies for cation diffusion were determined by fitting the conductivity data to the Arrhenius equation $\sigma = \frac{\sigma_0}{T}e^{E_a/k_BT}$. [Preview Abstract] 

C1.00338: Reveal protein dynamics by combining computer simulation and neutron scattering Liang Hong, Jeremy Smith Protein carries out most functions in living things on the earth through characteristic modulation of its threedimensional structure over time. Understanding the microscopic nature of the protein internal motion and its connection to the function and structure of the biomolecule is a central topic in biophysics, and of great practical importance for drug design, study of diseases, and the development of renewable energy, etc. Under physiological conditions, protein exhibits a complex dynamics landscape, i.e., a variety of diffusive and conformational motions occur on similar time and length scales. This variety renders difficult the derivation of a simplified description of protein internal motions in terms of a small number of distinct, additive components. This difficulty is overcome by our work using a combined approach of Molecular Dynamics (MD) simulations and the Neutron Scattering experiments [1]. Our approach enables distinct protein motions to be characterized separately, furnishing an indepth understanding of the connection between protein structure, dynamics and function [2,3]. \\[4pt] [1] L. Hong, \textit{et al.}, Phys. Rev. Lett. 107 (2011) 148102. \\[0pt] [2] L. Hong, \textit{et al.}, Phys. Rev. Lett. 108 (2012) 238102. \\[0pt] [3] L. Hong, \textit{et al.}, Phys. Rev. Lett. 110 (2013) 028104. [Preview Abstract] 

C1.00339: Anomalous magnetotransport properties of high doped Nb:SrTiO3 epitaxial films Suyoun Lee, Hyunwoo Jin, Inrok Hwang, Keundong Lee, JinGwan Joung, Jinsang Kim, Baeho Park, Sungwon Yoon, Byung Jin Seo, Sung Seok A. Seo Nbdoped SrTiO$_{3}$ (Nb:STO) has been extensively studied not only as a conducting substrate for the epitaxial growth of perovskite oxides, but also as a promising candidate for developing oxidebased high mobility twodimensional electron gas (2DEG) layer. However, most of the existing studies are focused on the properties of Nb:STO with low Nb concentration (mostly up to 5 at. \%). In this work, we investigated the magnetotransport properties of Nb:STO films with high Nb content and found anomalous properties such as magneticfield induced metalinsulator transition (MIT) and highly asymmetric magnetoresistance (MR). The magnetic field dependence of Hall resistance was found to be nonlinear indicating the involvement of more than two distinguished kinds of charge carriers in the transport. The measurement of DCmagnetization showed a signature of magnetic ordering at nearly the same temperature as the metalinsulator transition. We speculate that a chargedensitywave (CDW) phase induced by magneticfield might be formed in highly doped Nb:STO films leading to the observed anomalous transport properties. [Preview Abstract] 

C1.00340: Certifying Separability in Mixed States, and Superradiance Elie Wolfe, S.F. Yelin Separability criteria are typically of the necessarybutnotsufficient variety, in that satisfying some separability criterion, such as demanding positivity of all eigenvalues under partial transpose, does not strictly imply separability. Certifying separability amounts to giving an existence proof for a decomposition of target mixed state into some convex combination of separable states, however even determining the existence of such a decomposition is ``hard.'' We show that it is effective to instead ask if the target mixed state ``fits'' some preconstructed separable form, in that one can generate a sufficient separability criterion relevant to all target states in some family by ensuring enough degrees of freedom in the preconstructed separable form. We demonstrate this technique by inducing a sufficient criterion for ``diagonally symmetric'' states of N qubits. A sufficient separability criterion opens the door to study precisely how entanglement is (not) formed; we use ours to prove that, counterintuitively, entanglement is not generated in idealized Dicke superradiance despite the manybody effects of that model. We introduce a quantification of the extent to which a given preconstructed parametrization comprises the set of all separable states; for ``diagonally symmetric.'' [Preview Abstract] 

C1.00341: Strong spinorbit coupling arising from unusual pseudomorphism at the interface of the protonirradiated Co$_{3}$O$_{4}$/Pd superlattice Sanghoon Kim, Soogil Lee, Hyun Hwi Lee, SeongHun Park, JaeHoon Park, HanKoo Lee, Jongill Hong We previously reported that the proton irradiation induces reduction from an oxidic paramagnetic Co$_{3}$O$_{4}$/Pd superlattice to a metallic ferromagnetic Co/Pd superlattice without any noticeable damages, which is radically different from any other irradiation methods [1]. In this presentation, we demonstrate that such an enhancement of perpendicular magnetic anisotropy stems from the strong spinorbit coupling at the interface between the reduced Co and the metallic Pd layers. We found that Co atoms are pseudomorphically rearranged on the Pd atoms at the interfaces during reduction by the proton irradiation. This pseudomorphic rearrangement of the reduced Co atoms causes the significantly large interface magnetoelastic effect in the protonirradiated superlattice. The xray magnetic circular dichroism study shows that the orbital to spin moment ratio has increased by $\sim$30{\%} at the interface due to the strong pseudomorphism when we compare it with the metallic Co/Pd superlattice. This result signifies that the protonirradiated Co$_{3}$O$_{4}$/Pd superlattice has spinorbit coupling much stronger than the metallic superlattice. Our study has an important implication for generating spinorbit torque effects or observing new magnetic objects such as skyrmions in novel spintronic devices. \\[4pt] [1] Sanghoon Kim, et al. Nature Nanotechnology 7, 567 (2012). [Preview Abstract] 

C1.00342: Superconducting and Magnetic Properties of FeSe$_{\mathrm{1x}}$As$_{\mathrm{x}}$ Khalil Ziq, T. Owolabi, A. Salem Magnetic and transport measurements have been performed on \textbf{FeSe}$_{\mathrm{\mathbf{1x}}}$\textbf{As}$_{\mathrm{\mathbf{x}}}$ samples in the normal and superconducting state. The normal state resistivity increases to a broad maximum (T$_{\mathrm{m}}$ ) near room temperature that persists down to about 80K then linearly drops down to just above the superconducting transition temperature (T$_{\mathrm{c}})$. The normal state behavior of the resistivity is found to insensitive to the applied magnetic field. The normal state magnetic measurements revealed ferromagnetic like behavior for samples with Asdoping above x$=$ 4{\%}. Moreover; Tc is reduced drastically with increasing Asconcentration above 2{\%}. [Preview Abstract] 

C1.00343: Rotonmaxon excitation spectrum for Q2D weakly interacted dipolar excitons Aleksey Fedorov, Igor Kurbakov, Yurii Lozovik Remarkable progress was achieved in investigation of collective properties and BEC of quasiparticles, e.g., excitons and polaritons. As it well known their small effective mass provides sufficiently high BEC temperature. However, in reality excitons lifetime is not enough to achieve thermodynamical equilibrium. Spatial separation of electrons and holes in semiconductor layer suppresses recombination process, and exciton lifetime increases sufficiently. Moreover, the separation results in appearance of excitons dipole moments. We predict generation of rotonmaxon excitation spectrum for BEC of dipolar excitons in weak correlation regime in Q2D geometry of semiconductor layer. The effect of rotonmaxon spectrum is the result of attraction and anisotropy of dipoledipole interaction in Q2D geometry, and it can be viewed as residual phenomena of phonon collapse for 3D dipoles. According to our estimation effects of BEC and rotonmaxon spectrum are principally observable experimentally for excitons in crossed electromagnetic fields in GaAs heterostructures. [Preview Abstract] 

C1.00344: Multiple imputation as a means to assess Mammographic vs. Ultrasound technology in Determine Breast Cancer Recurrence Irene B. Helenowski, Hakan Demirtas, Seema Khan, Firas Eladoumikdachi, Ali Shidfar Tumor size based on mammographic and ultrasound data are two methods used in predicting recurrence in breast cancer patients. Which technology offers better determination of diagnosis is an ongoing debate among radiologists, biophysicists, and other clinicians, however. Further complications in assessing the performance of each technology arise from missing data. One approach to remedy this problem may involve multiple imputation. Here, we therefore examine how imputation affects our assessment of the relationship between recurrence and tumor size determined either by mammography of ultrasound technology. We specifically employ the semiparametric approach for imputing mixed continuous and binary data as presented in Helenowski and Demirtas (2013). [Preview Abstract] 

C1.00345: ABSTRACT MOVED TO H1.00132 

C1.00346: QuantumConfinement Effects on Optoelectronic Properties of ZnO Quantum Dots Nacir Tit We present a theoretical investigation on the optoelectronic properties of ZnO quantum dot (QD) embedded in MgO matrix. This latter material acts as huge barrier for both electrons and holes so that the ZnO QD behaves as a threedimensional quantum well. As a computational method, the tightbinding with sp$^{3}$ minimal basis set is employed to probe the electronic band structure and inspect the number and confinement energies of the bound states versus QD size (up to 20 {\AA}) and the valence band offset (VBO). Excellent agreement is achieved between theoretically obtained bandgap energy (E$_{\mathrm{g}})$ and experimental photoluminescence (PL) data, especially when VBO $=$ 1 eV which correspond to the maximum compromised confinements between holes and electrons. Furthermore, theoretical results show that the quantum confinement (QC) energy follows a powerlaw rule, indicating strong confinement, and is the main reason behind the UV emissions in ZnO QDs. The strong QC of excitons would further explain the enhancement of the oscillator strength and recombination rate. The excellent obtained agreements between our results and the available experimental data do corroborate our claims. [Preview Abstract] 

C1.00347: Tunable Absorption Enhancement with Graphene Nanodisk Arrays Yumin Wang, Zheyu Fang, Andrea Schlather, Zheng Liu, Pulickel Ajayan, Javier Garcia de Abajo, Peter Nordlander, Xing Zhu, Naomi Halas Extended singlelayer graphene has weak optical absorption at visible and infrared wavelengths, which severely reduces its potential for optoelectronic applications. Here, by tailoring a graphene layer into an array of closely packed graphene nanodisks, we improve its absorption efficiency from less than 3{\%} to 30{\%} in the infrared region of the spectrum. In addition, we demonstrate that this enhanced absorption depends on nanodisk size, interparticle spacing and voltagedriven electrostatic doping.[1] These finding suggests that graphene nanomaterials are promising media for infrared electrooptic devices. \\[4pt] [1] Z.Y. Fang et al., Nano Lett. 14(2014)10.1021/nl404042h [Preview Abstract] 

C1.00348: Response of TwoDimensional Statically Jammed Frictionless Disks at Constant Pressure to Increasing Pure Shear Stress Benjamin CohenStead, Yegang Wu, Stephen Teitel We perform numerical simulations of a model twodimensional granular system composed of a bidisperse distribution of softcore, circular, frictionless disks. Starting from randomly quenched, mechanically stable, configurations at fixed isotropic pressure above the jamming transition, we gradually increase the applied pure shear stress, under conditions of fixed pressure, until we reach the yield stress at which stability is lost and the system begins to flow. Averaging over many different initial configurations, we compute the average packing fraction and average shear and compressional strains, as the shear stress is increased to yielding. We find that the response of the system is nonmonotonic in the applied shear stress. As the shear stress initially increases from zero, the system compresses (packing fraction increases at fixed pressure); but at a shear stress equal to roughly 70{\%} of the yield stress, the system starts to dilate (packing fraction decreases at fixed pressure). [Preview Abstract] 

C1.00349: Precise photoionization yields of atomic hydrogen using intense fewcycle light pulses R.T. Sang, O. Gharfur, W.C. Wallace, J.E. Calvert, D.E. Laban, M.G. Pullen, A.N. GrumGrzhimailo, K. Bartschat, I.V. Litvinyuk, D. Kielpinski The interaction of intense fewcycle infrared laser pulses with matter is the fundamental process at the heart of strongfield science. The complex, highly nonlinear dynamics that occur in the regime of fewcycle laser pulses necessitate accurate theoretical simulations in order to retrieve useful physical measurements and provide a sensible physical interpretation of the experimental data. Strongfield ionization experiments involving atomic hydrogen (H) have been previously performed with a qualitative agreement to theory. Building on our earlier work, which obtained quantitative agreement at the 10{\%} level between simulations and measurements of photoelectron spectra in H [M. G. Pullen \textit{et al} 2011 \textit{Opt. Lett.} \textbf{36} 3660], we now extend this scheme to measurements of the total photoionization yield. We interact a fewcycle laser pulse with duration of 6 fs, 800 nm central with an H beam created though an RF discharge source. The ions that are created as a result of photoionization events are detected by a timeofflight mass spectra and an ionization yield is determined. [Preview Abstract] 

C1.00350: Dual surfacefunctionalized Janus nanocomposites for targeted stimulus responsive drug delivery. Feng Wang, Yilong Wang, Giovanni Pauletti, Donglu Shi A novel superparamagnetic Janus nanocomposite (SJNC) of polystyrene/Fe$_{3}$O$_{4}$@SiO$_{2}$ was designed and developed for the first time using a miniemulsion method. Both surfaces were readily functionalized for biomedical application. Folic acid (FA) and doxorubicin (DOX) were conjugated stepwise to the surfaces. It was found that SJNCs achieved celltargeted drug delivery in a pHresponsive manner. [Preview Abstract] 

C1.00351: Assessing Program Learning Objectives to Improve Undergraduate Physics Education Carrie Menke Our physics undergraduate program has five program learning objectives (PLOs) focusing on (1) physical principles, (2) mathematical expertise, (3) experimental technique, (4) communication and teamwork, and (5) research proficiency. One PLO is assessed each year, with the results guiding modifications in our curriculum and future assessment practices; we have just completed our first cycle of assessing all PLOs. Our approach strives to maximize the ease and applicability of our assessment practices while maintaining faculty's flexibility in course design and delivery. Objectives are mapped onto our core curriculum with identified coursework collected as direct evidence. We've utilized mostly descriptive rubrics, applying them at the course and program levels as well as sharing them with the students. This has resulted in more efficient assessment that is also applicable to reaccreditation efforts, higher interrater reliability than with other rubric types, and higher quality capstone projects. We've also found that the varied quality of student writing can interfere with our assessment of other objectives. This poster outlines our processes, resources, and how we have used PLO assessment to strengthen our undergraduate program. [Preview Abstract] 

C1.00352: Two types of Diraccone surface states on the (111) surface of the topological crystalline insulator SnTe Yusuke Tanaka, Takuya Shoman, Kosuke Nakayama, Seigo Souma, Takafumi Sato, Takashi Takahashi, Mario Novak, Kouji Segawa, Yoichi Ando We have performed angleresolved photoemission spectroscopy (ARPES) on the (111) surface of the topological crystalline insulator SnTe. Distinct from a pair of Diraccone surface states across the $\bar{X}$ point of the surface Brillouin zone on the (001) surface, we revealed two types of Diraccone surface states each centered at the $\bar{\Gamma}$ and $\bar{M}$ points, which originate from the bulkband inversion at the $L$ points. We also found that the energy location of the Dirac point and the Dirac velocity are different from each other. This ARPES experiment demonstrates the surface states on different crystal faces of a topological material, and it elucidates how mirrorsymmetryprotected Dirac cones of a topological crystalline insulator show up on surfaces with different symmetries. [Preview Abstract] 

C1.00353: Photoemission Spectroscopic Study on the Epitaxial Graphene Oxide Layer Produced by a Dry Process GwangEun Yang, Chanyong Hwang, M. Zahir Iqbal, Jonghwa Eom, Suklyun Hong, ByeongGyu Park, Wondong Kim Recently, graphene oxide layers have been studied intensively because various kinds of chemically modified graphene layers can be massively produced from functionalization of graphene oxide layers. Conventional methods to produce graphene oxides are based on the wet chemistry such as a modified Hummber method, but the lack of selectivity in oxidizing the graphene layers have been considered as the limit of the wetchemistry based method. In this study, we report by a simple dry process to produce graphene oxides layer from the epitaxial graphene by irradiation of deep UV light under the flow of dry oxygen gas. From the careful investigation by using photoemission spectroscopy, we could identify that the oxidized epitaxial graphene layers have the energy gaps between 1.6 and 2.0 eV, and they were thermally stable up to 700 K. We also examined the possibility of selective oxidization based on this dry process by using a photomask. [Preview Abstract] 

C1.00354: ElectronPhonon Coupling in Alkali Doped Bilayer Graphene Studied by ARPES James Kleeman, Katsuaki Sugawara, Takafumi Sato, Takashi Takahashi Graphene intercalation compounds are a class of materials consisting of stacked graphene sheets, with dopant adatoms ordered inbetween them. These materials exhibit an unusual superconducting state, for which characteristic electronphonon coupling has been suggested. Recent advances in angleresolved photoemission spectroscopy (ARPES) have enabled high precision measurement of electronphonon coupling in GICs. Coupling at the graphitederived $\pi$ bands was found to be highly anisotropic in the GIC KC$_8$, being much stronger in the KM than K$\Gamma$ directions [1]. This unusual anisotropy is not predicted by previous superconducting theories. A much smaller anisotropy has also been seen in recent studies of Kdoped graphene monolayers [2]. In order to examine the presence of anisotropic coupling in the graphenemetal system, we have performed ARPES on the bilayer graphene GIC [3]. We have found that C$_8$RbC$_8$ exhibits strong, anisotropic coupling, similar to that in GICs. The origin of this coupling, as well as its relation to possible superconductivity in ultrathin GICs is discussed.\\[4pt] [1] Gr\"uneis, A., et al. Phys. Rev. B, 79(20), 19 (2009).\\[0pt] [2] D. Haberer, et al. Phys. Rev. B 88, 081401 (2013).\\[0pt] [3] Kleeman, J., et al. Phys. Rev. B, 87(19), 195401 (2013) [Preview Abstract] 

C1.00355: Numerical Study of Broadband Disturbance Development in APG Boundary Layer Flow Weijia Chen, Jim Chen, Edmond Lo A numerical model is developed with combined compact difference methods to simulation boundary layer transition problems. The model is used to investigate the formation and development of coherent structures in late stage of a laminarturbulent transition initiated by a twodimensional TollmienSchlichting (TS) wave and initially weak broadband disturbances. The numerical simulation closely follows the conditions in the experiments by Borodulin (2006). The boundary layer base flow has an Adverse Pressure Gradient (APG) with Hartree parameter $\beta_{\mathrm{H}} \quad = \quad $0.115. The instantaneous flow structures are visualized, which demonstrate results comparable with experiments. Interaction between the TS wave and broadband disturbances leads to the formation of $\Lambda $vortices, $\Omega $vortices, and ringlike vortices. In comparison with those in classical transition paths, i.e., fundamental and subharmonic resonances, these structures are distributed in a random order and have distorted shapes. However, their local evolution properties are qualitatively similar with those in classical transition paths. [Preview Abstract] 

C1.00356: The Effect of Biaxial Strain and Layer Thickness on Octahedral Rotation in LaNiO$_3$ Patrick McBride, Anderson Janotti, Cyrus Dreyer, Burak Himmetoglu, Chris Van de Walle Heterostructures of complex oxides have attracted great attention for the interplay between structure, electronic, and magnetic properties, offering unique opportunities in device applications. Here we investigate the effects of epitaxial strain and layer thickness on the structural properties of LaNiO$_3$. We perform firstprinciples calculations based on density functional theory to investigate the NiO$_6$ octahedral tilts and NiO bond lengths of biaxially stressed LaNiO$_3$ layers in LaNiO$_3$/SrTiO$_3$ superlattices. Recent experimental results suggest that octahedral connectivity in these superlattices strongly influence the octahedral rotations in the LaNiO$_3$ layer, and thus, determines its electronic behavior. In this talk we will present a quantitative analysis for the octahedral tilt angles as a function of both biaxial stress and distance from the substrate for LaNiO$_3$ grown on SrTiO$_3$ (001). Our results indicate that LaNiO$_3$ exhibits vanishing octahedral tilt angles under certain strain conditions, a finding that holds important consequences for its electronic properties. [Preview Abstract] 

C1.00357: Quantum Coherence and Population Transfer in a Driven Cascade ThreeLevel Artificial Atom Sung Un Cho, Han Seb Moon, YoungTak Chough, MyungHo Bae, Nam Kim We present an experimental investigation on the spectral characteristics of an artificial atom ``transmon qubit'' constituting a threelevel cascade system ($\Xi $system) in the presence of a pair of external driving fields. We observe two different types of AutlerTownes (AT) splitting: Type I, where the phenomenon of twophoton resonance tends to diminish as the coupling field strength increases, and Type II, where this phenomenon mostly stays constant. We find that the types are determined by the cooperative effect of the decay rates and the field strengths. Theoretically analyzing the density matrix elements in the weak field limit where AT effect is suppressed, we single out events of pure twophoton coherence occurring owing to constructive quantum interference. [Preview Abstract] 

C1.00358: Thin film NMR T$_{\mathrm{1}}$ measurement by MRFM using cyclic adiabatic inversion Sungmin Kwon, SeungBo Saun, Soonchil Lee, Soonho Won We obtained the NMR spectrum and the spin lattice relaxation time (T$_{\mathrm{1}})$ for thin film samples using Magnetic Resonance Force Microscopy (MRFM). The samples were Alq$_{\mathrm{3}}$, which is widely used as an organic light emitting diode (OLED), thin films of 150 nm thick and a bulk crystal. T$_{\mathrm{1}}$ was measured by using the cyclic adiabatic inversion method at a fixed frequency of 297 MHz and at 12 K. To confirm the reliability of our measurement technique we compared the result with that obtained by conventional NMR method. T$_{\mathrm{1}}$ of thin film samples was measured and compared with that of the bulk sample. [Preview Abstract] 

C1.00359: Dryingmediated uniform coating of colloidal nanosheets Kun Cho, Byung Mook Weon, Takayoshi Sasaki When droplets with colloidal particles evaporate on a flat solid substrate, natural radial capillary flows are known to induce edgeward segregation of the colloidal particles, generating ringlike patterns, which is the coffeering effect. This hydrodynamic effect can be suppressed by changing the particle shape like ellipsoidal particles. Recently various nanosheets are under development as a form of suspensions for practical applications. Here we report a great possibility of selfassembled uniform coating based on twodimensional (2D) nanosheets. We adopted a colloidal suspension of Ca$_{\mathrm{2}}$Nb$_{\mathrm{3}}$O$_{\mathrm{10}}$ nanosheets whose thickness was about 2 nm and its lateral size was 3 micrometers. With a highresolution digital camera, we found that the deposition patterns are uniform, regardless of the substrate wettability and the droplet size. The uniform deposition would be attributed to the 2D anisotropy of the nanosheets. We believe that 2D nanosheets would allow us to obtain selfassembled uniform coating for inkjet printing. [Preview Abstract] 

C1.00360: ABSTRACT WITHDRAWN 

C1.00361: ABSTRACT MOVED TO P1.00326 

C1.00362: Pump saturation effect of the Er$^{3+}$/Yb$^{3+}$ codoped Y$_{2}$Ti$_{2}$O$_{7}$ phosphors containing nanocrystals Feng Song, Fengxiao Wang, Jun Zhang, GuiYang Chen, Ming Feng Er$^{3+}$ and Yb$^{3+}$ codoped Y$_{2}$Ti$_{2}$O$_{7}$ phosphors containing nanocrystals were prepared by solgel method and annealed at 800 $^{\circ}$C for 1 h in air. The Xray diffraction (XRD) and transmission electron microscope (TEM) images showed that the mean size of nanocrystals is about 4050nm, which corresponds well with the calculated results by Scherrer equation. Photoluminescence spectra and its upconversion properties were investigated. The anomalous slopes of the fitted line in the loglog plots for upconversion emissions and the pumpsaturation effect of near infrared (NIR) emission were observed in the nanocrystalline samples. The reasons for the highly efficient upconversion luminescence and pumpsaturation effect of NIR emission were discussed by a theoretical model of practical Er$^{3+}$/Yb$^{3+}$ codoped system based on the rate equations. [Preview Abstract] 

C1.00363: The edge engineering of topological Bi (111) bilayer Xiao Li, HaiWen Liu, Hua Jiang, Ji Feng A topological insulator is a novel quantum state, characterized by symmetryprotected nontrivial edge/surface states. Our firstprinciple simulations show the significant effects of the chemical decoration on edge states of topological Bi (111) nanoribbon, such as the recovery of the linear dispersion and the extension of the penetration depth. A lowenergy effective model is proposed to explain the distinctive spin texture of Bi (111) bilayer nanoribbon, which is different from the spinmomentum orthogonality paradigm of topological insulators. In particular, the Bi (111) bilayer nanoribbon offers a simple system for assessing conductance fluctuation of topological edge states, by comparing the edge states with and without chemical decoration. [Preview Abstract] 

C1.00364: Effect of Electromagnetic Fields on the Transportation of Nutrients in Fluids and its Effect on the Bacterial Growth Samina Masood We study the effect of electromagnetic fields on the transport properties of nutrients in fluids through their effect on the growth of bacteria. For this purpose we study the growth of bacteria in the presence of different type of magnetic fields and relate the relative change in the growth rates in different fields to the change in the transport of nutrients in the fluids. We use static magnetic field, electromagnetic field and the randomly changing magnetic field for this purpose. We manly concentrate on weak field effect due to their relevance with the daily life. [Preview Abstract] 

C1.00365: A DensityFunctionalPerturbationTheory Study of Superconducting Nb3Sn Under UniaxialStrain Peter Byrne The effects of strain on superconducting Nb$_3$Sn are of great interest because they cause significant changes in the performance of these materials during both cooldown and energisation of high field magnets and they give us an insight into the basic superconducting mechanism. There is a lot of experimental data describing these effects because this material is to be used in ITER, but a detailed firstprinciples understanding is not yet available. In this computational study, a unit cell of Nb$_3$Sn was subjected to a range of uniaxial strains and allowed to relax fully within a periodic density functional perturbation theory (DFPT) scheme. First order DFPT was then used to calculate the effects of electronphonon coupling at each strain. The data obtained are compared with experimental measurements on single crystals as well as on wires made using both the ``powder in tube'' and ``bronze route'' methods. The calculated values for the strain dependence of the critical temperature ($T_C$) agree to within 20\% with the experimental data and the peak in $T_C$ found under compression may help improve our understanding of the experimental result that $T_C$ of the tetragonal phase is higher than that of the cubic phase. [Preview Abstract] 

C1.00366: Numerical Aspects of Atomic Physics: Helium Basis Sets and Matrix Diagonalization Ulrich Jentschura, Jonathan Noble We present a matrix diagonalization algorithm for complex symmetric matrices, which can be used in order to determine the resonance energies of autoionizing states of comparatively simple quantum manybody systems such as helium. The algorithm is based in multiprecision arithmetic and proceeds via a tridiagonalization of the complex symmetric (not necessarily Hermitian) input matrix using generalized Householder transformations. Example calculations involving socalled PTsymmetric quantum systems lead to reference values which pertain to the imaginary cubic perturbation (the imaginary cubic anharmonic oscillator). We then proceed to novel basis sets for the helium atom and present results for Bethe logarithms in hydrogen and helium, obtained using the enhanced numerical techniques. Some intricacies of ``canned'' algorithms such as those used in LAPACK will be discussed. Our algorithm, for complex symmetric matrices such as those describing cubic resonances after complex scaling, is faster than LAPACK's builtin routines, for specific classes of input matrices. It also offer flexibility in terms of the calculation of the socalled implicit shift, which is used in order to ``pivot'' the system toward the convergence to diagonal form. We conclude with a wider overview. [Preview Abstract] 

C1.00367: A Periodic Dielectric Resonator Structure for Terahertz Wave Amplification Olutosin Fawole, Massood TabibAzar We present a periodic Slow Wave Structure (SWS) that consists of an arrangement of closely spaced cylindrical resonators with low dielectric constant. In this compact arrangement, coupling between resonators was via evanescent field coupling. This arrangement contrasts earlier infinite high dielectric constant SWSs with widely spaced resonators coupled via magnetic dipole moments. The presented periodic structure is an alternative to the metallic slow wave structures that have been proposed for TWT THz amplifiers. The fabricated low frequency (8 GHz) prototype of our structure consists of an array of cylindrical resonators with dielectric constant 9.2, diameter 12 mm, and height 6.35 mm. Slow waves, which setup a TE$_{\mathrm{01\delta }}$like electric field mode in each resonator, propagate in the structure when then the structure was excited with a microstrip line. We will present detailed simulation and experimental results of this prototype at the conference. Furthermore, efforts to scale the SWS to THz frequency and to interact the SWS with highenergy particle beams will be presented. [Preview Abstract] 

C1.00368: Enhancing the public impact of the Higgs discovery and other fundamental physics research Suzy Lidstrom, Alex Read, Stephen Parke, Roland Allen, Steven Goldfarb, Sascha Mehlhase, Tord Ekelof, Alan Walker The recent experimental discovery of a Higgs boson by the ATLAS and CMS collaborations at the LHC, together with the awarding of the 2013 Nobel Prize for its theoretical prediction, has presented an exceptional opportunity for public outreach regarding the goals and importance of fundamental research in physics. We discuss novel avenues for further extending this outreach in all areas. These range from tutorial papers addressing students and teachers to internet resources and presentations to unconventional, but captivating, educational materials such as musical videos and LEGO models. Interaction with active scientists can be particularly stimulating. We account how this was encouraged (by means such as badges inviting questions from the public) during Nobel week and afterwards. \textit{The 2013 Nobel Prize in Physics explained} [Preview Abstract] 
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