Bulletin of the American Physical Society
49th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics APS Meeting
Volume 63, Number 5
Monday–Friday, May 28–June 1 2018; Ft. Lauderdale, Florida
Session E01: Poster Session I 
Hide Abstracts 
Room: Hall D 

E01.00001: Observation of Isomerization Hindering of DCVJ on Nanostructured Surfaces Trevor Olsson, Patrick Fowler, Laszlo Ujj We report molecular vibrational characterization of 9Dicyanovinyl julolidine (DCVJ) with surface enhanced Raman spectroscopy (SERS), and we report a construction of a tabletop laser micro Raman optical system. We used two different SERS substrates, one with nanoparticles and the second was a silvercoated nanopillar structure. Onemicroliter volume of DCVJ/MEOH solution was deposited on the surface of our substrates, with no significant spectral differences observed on the recorded vibration spectra. Compared with spectra recorded from methanol solution showed band shifts and altered intensity pattern. Based on the normal modes analysis, we associate the spectral changes to the blocking of the isomerization of the rotor part of the molecule absorbed on the silver nanostructures. The results contribute to the understanding of the underlining physical processes of Raman scattering enhancements by plasma resonances. [Preview Abstract] 

E01.00002: DFT Calculation of the Renner Coefficient for the RennerTeller Splitting in the NCO radical: Assessing the accuracy of several common functional families and basis sets D. O. Kashinski, M. G. Suarez, C. C. Stephens, E. F. C. Byrd The ``out of box'' DFT calculation of the Renner coefficient for the RennerTeller splitting in the NCO radical using functionals from the B3LYP, PBE, TPSS, M06, and M11 functional families with standard Correlation Consistent ccpV$x$Z and augccpV$x$Z ($x=$ D, T and Q), 6311G split valence family, as well as Sadlej, and Sapporo polarized triple$\zeta$ basis sets is being completed. Quantum chemistry calculations are being completed using the GAUSSIAN16 suite on DoDHPCs. A comparison of our results to previously published theory and experimental results will be made to assess the accuracy of the functional and basis set combination. The impact of functional and basis set choices on the resulting coefficients will be characterized. An update on the progress of this work will be given at the meeting. [Preview Abstract] 

E01.00003: Measurement of the Electron Affinity of Thallium by Photodetachment Threshold Spectroscopy C.W. Walter, N.D. Gibson, G.R. Drumm, Y. Li, S.M. Miller The electron affinity of thallium has been measured using tunable laser photodetachment threshold spectroscopy. The relative cross section for neutral atom production following photodetachment from Tl$^{}$ was measured with a crossed laserion beam apparatus over the photon energy range 0.30  0.50 eV. An \textit{s}wave threshold was observed due to the opening of the Tl$^{}$ (6\textit{p}$^{2}$ $^{3}$\textit{P}$_{0}$) to Tl (6\textit{p} $^{2}$\textit{P}$_{1/2}$) groundstate to groundstate transition, yielding a preliminary value for the electron affinity of thallium. The electron affinity measured in the present work is compared with previous experimental [1] and theoretical [2] results. \\[4pt] [1] D. L. Carpenter, A. M. Covington, and J. S. Thompson, \textit{Phys. Rev. A} \textbf{61}, 042501 (2000); [2] see for example J. Li, Z. Zhao, M. Andersson, X. Zhang, and C. Chen, \textit{J. Phys. BAt. Mol. Opt. Phys.} \textbf{45}, 165004 (2012). [Preview Abstract] 

E01.00004: Millimeterwave spectroscopy of Rydberg states in potassium Charles Conover, Huan Bui, Gabriel Forest We report highprecision measurements of millimeterwave transitions between Rydberg states in potassium. We make measurements in a magnetooptical trap with a temperature of 12 mK and peak atomic density of $10^9$ atoms/cm$^3$. The cold atoms are excited to Rydberg states in steps from $4s$ to $5p$ and from $5p$ to $ns$ and $nd$ states using stabilized externalcavity diode lasers at 405 nm and 980 nm. Millimeterwave transitions are detected by selective field ionization. We null stray electric fields in three dimensions using potentials applied to a set of mutually perpendicular rods surrounding the MOT cloud. The measured frequency intervals are measured to better than a part in 10$^7$ and are then used to determine the quantum defects and absolute energies of the Rydberg states. [Preview Abstract] 

E01.00005: Highresolution xray spectra of highly charged tungsten produced in an electron beam ion trap Samuel Sanders, Amy Gall, Hemalatha Rudramadevi, Roshani Silwal, Joan Dreiling, Yuri Ralchenko, Endre Takacs Highly charged tungsten ions present in fusion devices require experimental data to fully characterize the plasma. We present highresolution xray spectra of highly charged W in the wavelength range of 4.8 {\AA}  5.0 {\AA}. Line identification was aided by simulated results from a nonMaxwellian collisional radiative model (NOMAD), where the strongest transitions arise from 3d4f resonances. The W plasma was produced and confined in an electron beam ion trap, and the spectra were recorded with a highresolution Johanntype Braggreflection xray spectrometer [1]. Electron beam energies ranging between 5.2 keV and 6.5 keV explored the variations in the spectral features for particular chargestate distributions. Coincident highresolution EUV and broadband xray spectra were also recorded to supplement the highresolution xray measurements. We discuss the application of our results to plasma research, highlighting the particular benefits to fusionplasma diagnostics. [1] Sanders et al., \textit{Nuc. Instrum. Meth. B}, Submitted for publication (2018). [Preview Abstract] 

E01.00006: Measuring Core Polarizability Of $^{87}$RB Using RF Spectroscopy Of Rydberg States Seth Berl, Charles Sackett, Thomas Gallagher The core electrons make a significant contribution to the total electric polarizability $\alpha$ of large atoms like Rb. If the core contribution can be determined accurately, the remaining valence contribution to $\alpha$ provides constraints on the wave function and matrix elements of the valence electron, which can be useful for interpreting experiments such as parity violation or radiation shifts in atomic clocks. We report here on a direct measurement of the core polarizability based on radiofrequency spectroscopy of Rydberg states with large angular momentum. With accuracy in $\alpha$ approaching 0.01 atomic units, the residual uncertainty will be negligible even in the most sensitive applications. The measured value can also be compared to highprecision theoretical calculations to test manybody techniques. [Preview Abstract] 

E01.00007: Precision measurements of excited state atomic lifetimes using a combination of continuous and ultrafast lasers Jerry Sell, Brian Patterson, Alina Gearba, Randy Knize, Stephen Spicklemire Atomic dipole matrix elements can be determined with high precision by measuring the corresponding excited state atomic lifetime. Measurements in Rb and Cs are important as they provide a test of atomic structure calculations, which are needed to properly interpret atomic parity violating experiments. Optical lattice atomic clocks can also benefit from these measurements as atomic dipole matrix elements play a role in correcting for the frequency shifts due to blackbody radiation. We will present our technique for precisely measuring the excited state lifetime of the Rb 5$P_{\mathrm{3/2\thinspace }}$state, which employs a combination of continuous and ultrafast lasers interacting with counterpropagating atomic beams. This arrangement produces a large signal with small noise, while seeking to minimize various systematic effects such as quantum beating, effects from atomic motion, and radiation trapping. We will present the level of precision in our current measurements in Rb, along with discussing future measurements in Yb and Sr. [Preview Abstract] 

E01.00008: Velocity selective optical pumping effects in electromagnetically induced absorption for $^{\mathrm{85}}$Rb atoms: polarization dependences HeungRyoul Noh, HaEun Hong, Zeeshan Jadoon, JinTae Kim We present experimental and theoretical studies on velocity selective optical pumping effects on electromagnetically induced absorption for the F$_{\mathrm{g}}=$3$\to $F$_{\mathrm{e}}=$2,3, and 4 transitions of $^{\mathrm{85}}$Rb atoms. Probe transmittance spectra are investigated by scanning the coupling laser frequency from the F$_{\mathrm{g}}=$3$\to $F$_{\mathrm{e}}=$2,3, and 4 transitions with a weak probe laser resonant to the F$_{\mathrm{g}}=$3$\to $F$_{\mathrm{e}}=$4 transition of $^{\mathrm{85}}$Rb atoms. We consider laser linewidth, atomic thermal velocity distributions, frequency mixings of coupling and probe beams due to degenerate magnetic sublevels, and various polarization configurations of the coupling beam with a probe beam fixed at $\sigma^{\mathrm{+}}$ polarization in the simulation of the spectra. We find good agreement between the calculated and observed transmittance spectra for each coupling laser polarization configuration. [Preview Abstract] 

E01.00009: Towards laser spectroscopy of isolated highly charged ions Eric Norrgard, Aung Niang, Angela Small, Joseph Tan We report on progress towards laser spectroscopy of several highly charged ion (HCI) species produced in an electron beam ion trap (EBIT) and transferred to a unitary Penning trap. Hlike Rydberg atoms will be prepared by charge exchange between trapped bare nuclei and a beam of Rydberg Rb atoms. Laser spectroscopy of Hlike Rydberg HCIs is insensitive to nuclear size or interactions, which should allow precise measurement of the Rydberg constant. Another application would monitor fluorescence decay of metastable states, excited either by a resonant laser or by electron bombardment in the EBIT, to measure the forbidden transitions of HCIs that are potentially useful in developing optical clock transitions or quantum information processing. Progress in constructing a novel compact apparatus will also be presented. [Preview Abstract] 

E01.00010: Rotationalstateselective field ionization of triplet molecular Rydberg states of H$_{\mathrm{2}}$ Will Setzer, James Dietz, Dylan Jones, T. J. Morgan We present rotationalstateselective field ionization spectra of highly excited triplet Rydberg states of molecular hydrogen. The experimental technique employs a fast 6 keV Rydberg molecular beam and a tunable static electric field of up to 40 kV/cm. The metastable c $^{\mathrm{3}}\prod _{\mathrm{u}}^{\mathrm{\thinspace }}$ 2p$\pi $ state, prepared by electron capture of 6 keV H$_{\mathrm{2}}^{\mathrm{+}}$ ions in potassium vapor, is excited by a frequency doubled tunable dye laser to access the v$=$0 R(1)nd1 (n$=$2127) Rydberg series. In each Rydberg state's field ionization spectra we observe multiple classical field ionization thresholds corresponding to the rotational states of the H$_{\mathrm{2}}^{\mathrm{+}}$ core. A model, based on diabatic traversal of the Stark map, is used to explain the data. [Preview Abstract] 

E01.00011: Photoionization cross sections for polyatomic molecules with the overset grid implementation of the complex Kohn variational method Loren Greenman, Robert Lucchese, C. William McCurdy With the recent implementation of the complex Kohn variational method on an overset grid [Phys. Rev. A 96, 052706 (2017)], we have extended the capabilities of variational scattering methods to complex molecules and exact treatments of the exchange interaction. This opens the door to accurate descriptions of correlated electron scattering processes, with implications for processes like the dissociative electron attachment to uracil. Here, we present an extension of this technique to the calculation of electronion scattering and photoionization cross sections. This is accomplished by matching to Coulomb functions on a boundary. [Preview Abstract] 

E01.00012: Understanding the lack of sitespecificity in molecular innershell photofragmentation Linda Young, Ludger Inhester, Bart Oostenrijk, Minna Patanen, Esko Kokkonen, Stephen Southworth, Christoph Bostedt, Oksana Travnikova, Tatiana Marchenko, Marc Simon, Robin Santra, SangKil Son, Stacey Sorensen In many cases fragmentation of molecules upon innershell ionization loses the specificity associated with the initially localized ionization site. Often this is interpreted in terms of an equilibration of internal energy into vibrational degrees of freedom after Auger decay. Here we investigate the xray photofragmentation of ethyl trifluoroacetate, the iconic ESCA molecule, upon core electron ionization at environmentally distinct carbon sites using photoelectronphotoionphotoion coincidence measurements and abinitio electronic structure calculations. For all the 4 carbon ionization sites, the Auger decay weakens the same bonds and transfers the two charges to opposite ends of the molecule, which leads to a rapid dissociation into 3 fragments followed by further fragmentation steps. The lack of sitespecificity is attributed to the character of the dicationic electronic states after Auger decay, instead of a fast equilibration of internal energy. [Preview Abstract] 

E01.00013: Xray Absorption of Atomic Si at the Kedge and Atomic Fe at the Ledge Tom Gorczyca, M. Fatih Hasoglu Largescale Rmatrix calculations are performed in order to compute the photoabsorption cross sections for the complicated thirdrow atomic Si and Fe systems. Calculations are carried out first for atomic Si near the 1.85 Kedge threshold. An atomic photoabsorption cross section is needed for Si to better understand the observed nearthreshold Chandra xray spectrum absorption in the interstellar medium (ISM). Predominantly condensedmatter Si absorption is observed, but the abundance of atomic silicon and its absorption effect is unknown. Calculations are also carried out for atomic Fe photoabsorption near the finestructure split 2pvacancy Ledge thresholds (707 eV and 720 eV). Reliable cross sections for this region therefore require a semirelativistic BreitPauli Rmatrix calculation, although nonrelativistic calculations, plus a LSJK frame transformation, yield meaningful results as well. The Si and Fe abundances in the ISM are usually assumed to be in the condensed matter state (ice, dust, etc.), and only condensedmatter absorption experiments have been carried out for either of these elements, necessitating a theoretical approach, such as the present Rmatrix method, to investigate atomic absorption in the ISM. [Preview Abstract] 

E01.00014: Double photoionization of atomic carbon and neon Frank Yip, Thomas Rescigno, C. William McCurdy Double photoionization events provide a direct probe of electron correlation, and focus on fewelectron targets continues to reveal the consequences of electron correlation for atoms and molecules that possess several electrons. We consider the double photoionization of the $2p^2$ valence electrons of atomic carbon, which provides for distinct finalstate symmetries depending on the three possible angular momentum couplings ($^3P$, $^1D$, and $^1S$) of the initiallybound $p^2$ that are ejected into the continuum by a single photon. Comparison of this process with neon provides an analogous case for the resulting final states within the treatment of the double photoionization proceeding with the ejected electrons influenced by the remaining bound electrons. Fullydifferential cross sections for both carbon and neon are compared. [Preview Abstract] 

E01.00015: Kinematically complete investigations of the Photo Double Ionization of N2 and O2 near threshold A. Gatton, I. Bocharova, F.P. Sturm, B. Gaire, M. Honig, P. Braun, M. Pitzer, D. Metz, H.K. Kim, W. Cao, J.B. Williams, A.L. Landers, Th. Weber We present the first Fully Differential Cross Sections (FDCSs) in the single Photon Double Ionization (PDI) of the many electron molecular systems $O_2$ and $N_2$. Both measurements were taken at beamline 10.0.1 of the Advanced Light Source, with 50eV photons for $N_2$ and 46eV photons for $O_2$. We present three dimensional distributions (theta, phi, yield) of the photoelectron in the body fixed frame after quadruple differential gating on: the initial state of the molecule, the electron energy sharing, the orientation of the polarization vector relative to the molecular axis, and the emission direction of one photoelectron in the molecular frame. We compare these distributions to the FDCSs of the PDI of $H_2$ and show profoundly different emission patterns indicating complex electronelectron correlation. [Preview Abstract] 

E01.00016: Inter Coulombic Decay of Molecular Dimer Wael Iskandar, Averell Gatton, Bishwanath Gaire, Kirk Larsen, Elio Champenois, Niranjan Shivaram, Ali Moradmand, Travis Severt, Joshua Williams, Daniel Slaughter, Itzik BenItzhak, Thorsten Weber Excited system embedded in environment can efficiently transfer its energy to neighboring species by ionizing them. This ultrafast deexcitation is known as the InterCoulombic Decay (ICD). Theoretical and experimental investigation showed that the ICD is a very common decay route in nature as it occurs after exciting a loosely bound system (e.g. vanderWaals or Hydrogen bonds) by ions, electrons, or photons. These studies showed that the secondary electrons emission from the ICD process induce strand breaks damage to DNA and may be used as well for DNA repair enzymes (i.e. photolyases). Studying large complex system such as multiatomic molecular dimer is very important for further exploration of Auger electron driven cancer therapy. The present experiment was performed at the Advanced Light Source in Berkeley using 37 to 55 eV of photon energies in order to investigate the dissociation dynamics of CO$_2$ and O$_2$ dimers. We focused more specifically on the doubly charged symmetric fragmentation channel of both dimers. The 3D momentum reconstruction of all detected fragments and electrons reveals that the ICD plays an important role on the production of both fragmentation channels. [Preview Abstract] 

E01.00017: Observations of ionpair, heavy Rydberg states above the third dissociation limit of $\rm H_2$ Alexander Chartrand, Robert Ekey, Elizabeth McCormack Resonantlyenhanced multiphoton ionization via the $EF\;{}^1 \Sigma_g^+$, $v'=6$ doublewell state has been used to probe the energy region from the third dissociation limit through the $n=4$ dissociation limit of H$_2$. Ionpair states with principal quantum number $n^*=206318$ are observed indirectly via mixing with the $n=3$ continuum. Previous observations of the ionpair, heavy Ryberg states support a diabatic picture of the avoided crossing of the adiabatic $B''\!\bar{B}\,^1\Sigma_u^+$ state with the ionpair potential at the third dissociation limit. These higher energy observations of ionpair states allow for a clearer picture of the energy dependence of the quantum defect as the series nears the fourth dissociation limit. We summarize the previous analysis and incorporate these new observations into the overall quantum defect picture. [Preview Abstract] 

E01.00018: Direct SinglePhoton Double Photoionization of NH$_{\mathrm{3}}$ at 61.54eV Investigated Using Coincidence 3D Momentum Imaging. Thorsten Weber, Kirk A. Larsen, Saijoscha Heck, Averell Gatton, Wael Iskandar, Elio G. Champenois, Richard Strom, Travis Severt, Bethany Jochim, Itzik BenItzhak, Dylan Reedy, Joshua B. Williams, Zachary Streeter, C. William McCurdy, Robert R. Lucchese, Thomas N. Rescigno, Daniel S. Slaughter We present stateselective measurements on various H$^{\mathrm{+}} \quad +$ H$^{\mathrm{+}}$ dissociation channels in neutral NH$_{\mathrm{3}}$ following direct singlephoton double photoionization (DPI) at 61.54eV. Here, the two photoelectrons and two protons are measured in coincidence using 3D momentum imaging, providing insight into the details of the electron and nuclear dynamics that ensue following direct singlephoton DPI. Results indicate that four dication electronic states contribute to H$^{\mathrm{+}} \quad +$ H$^{\mathrm{+}}$ dissociation. Three of these states result in equal energy sharing between the two protons, while the fourth results in unequal energy sharing between the two protons. Molecular plane proton momentum distributions suggest the three former states dissociate in a single step, while the later state fragments in multiple steps. Complementary photoelectron momentum distributions and singly differential cross sections for these states provide information on the mechanisms and energetics involved in the direct singlephoton DPI process. [Preview Abstract] 

E01.00019: Xray emission measurements following charge exchange between Ne$^{8+}$ and He. C. C. Havener, R. T. Zhang, D. G. Seely, V. M. Andrianarijaona, D. Wulf, F. Jaeckel, D. McCammon With a highresolution xray quantum microcalorimeter detector, xray emissions following single charge exchange are measured for Ne$^{8+}$ + He collisions at solar wind velocities (392 km/s to 876 km/s). To investigate the $(n,l)$ distributions of the captured electron, Balmer series line ratios are compared to ratios constructed from Multichannel LandauZener (MCLZ) calculations by Lyons et al. (Astrophys. J 232, 27 (2017)). Such MCLZ calculations are used to produce atomic data needed to model xray emissions from a variety of astrophysical objects. It is found that the measured line ratios are in excellent agreement with the calculations for the 4s $\rightarrow$ 4p emission. However, compared to the MCLZ theory, the measured line ratios indicate an increasing stateselectivity for the $4d$ and $4f$ states. Currently the apparatus is being modified to perform xray emission measurements for highly charged ions colliding with atomic H using the mergedbeam technique. [Preview Abstract] 

E01.00020: Electron and photonmolecule data for hydrogen plasmas Mark Zammit, James Colgan, David Kilcrease, Christopher Fontes, Jeffery Leiding, Peter Hakel, Eddy Timmermans, Dmitry Fursa, Liam Scarlett, Jonathan Tapley, Jeremy Savage, Igor Bray Studies of lowtemperature plasmas both in local thermodynamic equilibrium (LTE) and nonLTE require stateresolved (electronic, vibrational and rotationally resolved) transition cross sections or rate coefficients of molecules to calculate populations (for nonLTE plasmas), opacities and emissivities. Recently we developed ab initio methods and general codes to calculate electron and photonmolecule collision data of hydrogen H2 [1,2], the ion H2$+$ [3,4] and the isotopologues. We highlight results that differ with commonly ``accepted'' and used data, which may have implications in astrophysics and fusion plasma modeling. For example, we note that for material temperatures T\textless 2000 K, isotopic effects should be take into account to obtain LTEaveraged photodissociation cross sections accurate to better than 1020{\%}. [1] M. C. Zammit et al. Phys. Rev. Lett. 116, 233201 (2016) [2] M. C. Zammit et al. Phys. Rev. A 95, 022708 (2017) [3] M. C. Zammit et al. Phys. Rev. A 90, 022711 (2014) [4] M. C. Zammit et al. Astrophys. J. 851, 64 (2017) [Preview Abstract] 

E01.00021: Analysis of highspeed rotating flow inside gas centrifuge casing Dr. Sahadev Pradhan The generalized analytical model for the radial boundary layer inside the gas centrifuge casing in which the inner cylinder is rotating at a constant angular velocity $\Omega $\textit{\textunderscore i}while the outer one is stationary, is formulated for studying the secondary gas flow field due to wall thermal forcing, inflow/outflow of light gas along the boundaries, as well as due to the combination of the above two external forcing. The analytical model includes the sixth order differential equation for the radial boundary layer at the cylindrical curved surface in terms of master potential ($\chi )$, which is derived from the equations of motion in an axisymmetric $(r  z)$plane. The linearization approximation is used, where the equations of motion are truncated at linear order in the velocity and pressure disturbances to the base flow, which is a solidbody rotation. Additional approximations in the analytical model include constant temperature in the base state (isothermal compressible Couette flow), high aspect ratio (length is large compared to the annular gap), high Reynolds number, but there is no limitation on the Mach number. The discrete eigenvalues and eigenfunctions of the linear operators (sixthorder in the radial direction for the generalized analytical equation) are obtained. The solutions for the secondary flow is determined in terms of these eigenvalues and eigenfunctions. These solutions are compared with direct simulation Monte Carlo (DSMC) simulations and found excellent agreement (with a difference of less than 15{\%}) between the predictions of the analytical model and the DSMC simulations, provided the boundary conditions in the analytical model are accurately specified. [Preview Abstract] 

E01.00022: Energy Split in the SpinOrbit Coupling Bose Polaron Xingze Qiu, Wei Yi We first analytically solve the threebody physics, one impurity interacts respectively with two Bosons, which energy spectrum behaves the property of Efimov physics. When the two Bosons have spinorbit coupling, we find that the energy level splitting. We also consider this effect in the many body physics, and the splitting is further obvious. [Preview Abstract] 

E01.00023: Reactive collisions in $^{\mathrm{7}}$Li$_{\mathrm{2}}$ with large initial rotation Mark Rosenberry, Jacob Fanthorpe, Brian Stewart The study of molecular collisions is fundamental to astronomy and chemistry.~ We present results for collisions of $^{\mathrm{7}}$Li$_{\mathrm{2}}$ with $^{\mathrm{7}}$Li within a heat pipe.~ These reactive collisions can be observed at odd deltaj values, unlike the simple inelastic collisions of a noble gas atom with the dimer.~ Our present work is compared against previous values obtained for low initial j, and also against predictions made using quasiclassical trajectory calculations.~ We will also comment on VR resonance, observed for this transition in collisions between $^{\mathrm{7}}$Li$_{\mathrm{2}}$ and Ne.~~ [Preview Abstract] 

E01.00024: Auger Processes in Carbon Ions S. A. AbdelNaby, M. S. Pindzola A timedependent closecoupling method is used to calculate the double autoionization of C+3 2s2 2p. Initial states are obtained by relaxation in imaginary time, while autoionization rates are obtained by propagation in real time. Preliminary timedependent closecoupling results are presented for the triple autoionization of C+2 2s2 2p2. [Preview Abstract] 

E01.00025: ElectronImpact Ionization of the Si Atom S. D. Loch, M. S. Pindzola Distortedwave calculations are made for the electronimpact ionization of the 1s2 2s2 2p6 3s2 3p2 ground configuration of the Si atom. Direct ionization of the 3s and 3p subshells contribute to single ionization, while the direct ionization of the 2p subshell contributes to double ionization. The large excitationautoionization contributions from the 3s > 3p transition are examined in detail. The 3s2 3p2 3P > 3s 3p3 1D,3S,and 1P contributions are found to be located just above threshold and are found to be quite large. [Preview Abstract] 

E01.00026: Excitation of the 2$S$ state of atomic Hydrogen by Electron Impact Anand Bhatia The excitation cross sections of the 2$S$ state of atomic hydrogen at low incident electron energies have been calculated using the variational polarized method for electron energy between the range 10.30 and 54.5 eV. Nine partial waves are used to get convergence of cross sections in the above energy range. The maximum of the cross section is 0.137 $\pi a_{\mathrm{0}}^{\mathrm{2\thinspace }}$at 11.14 eV which is close to the experimental result 0.163 $\pi a_{\mathrm{0}}^{\mathrm{2}}$ at 11.6 eV. The present results are compared with other calculations, many of them based on the closecoupling approximation. Differential and spinflip cross sections have also been calculated. [Preview Abstract] 

E01.00027: Lowenergy electron scattering from atomic Th, Pa, U and Np using the Regge pole methodology Zineb Felfli, Alfred Z Msezane Here we investigate negative ion formation in lowenergy electron collisions with the actinide atoms Th, Pa, U and Np through the elastic total cross sections (TCSs) calculations. For these atoms, the presence of two or more open d and f subshell electrons presents a formidable computational task for conventional theoretical methods. Our robust Regge pole methodology which embeds the crucial electron correlations and the vital polarization interaction is used for the calculations. These are the major physical effects responsible for stable negative ion formation in lowenergy electron scattering. We find that the TCSs are characterized generally by RamsauerTownsend minima, shape resonances and dramatically sharp resonances manifesting ground and metastable anionic formation during the collisions. The extracted from the TCSs ground states anionic binding energies (BEs) are found to be 3.09 eV, 2.98 eV, 3.03 eV and 3.06 eV for Th, Pa, U and Np, respectively. We also found that our highest excited states anionic BEs for these atoms compare well with the calculated EAs using the relativistic configurationinteraction method [1]. Interestingly, the ground states anionic BEs for these actinides are comparable to those for the fullerenes [2]. 1. K. D. Dinov and D. R. Beck, Phys. Rev. A \textbf{52}, 2632 (1995); A \textbf{53}, 4031 (1996) 2. Z. Felfli and A. Z. Msezane, Euro Phys. J. D Submitted (2017) [Preview Abstract] 

E01.00028: Dissociative electron attachment of polyatomic molecule at low collision energies: application to H$_2$CN Viatcheslav Kokooulin, Samantha Fonseca dos Santos, Chi Hong Yuen Dissociative electron attachment (DEA) of molecules is an important process in various plasma environment. Despite several approaches developed for diatomic molecules, the theoretical description of the DEA for polyatomic molecules is an extremely complex problem. Following the treatment proposed by Bardsley (1968) developed for diatomic molecules, we extend the formalism of resonant scattering to polyatomic molecules, assuming that there is no vibrational excitation. We applied our method to the H$_2$CN molecule, which has six normal modes and is responsible for the formation of the CN$^$ and H$^$ ions and the HCN molecule in the interstellar space. Positions and widths of the resonances responsible for DEA process are computed using the UK Rmatrix code. The partial width for the electron capture is obtained from the timedelay matrix. With the new model, the total DEA cross section for H$_2$CN molecule is computed. [Preview Abstract] 

E01.00029: Dynamic and Optical Control of Sympathetically Cooled Chemistry in a Hybrid Trap Prateek Puri, Michael Mills, Elizabeth West, Christian Schneider, Eric Hudson We present a series of experiments conducted with the MOTion trap  an atomion hybrid apparatus consisting of a linear quadrupole trap (LQT) and colocated magnetooptical trap. We investigate chemistry occurring between neutral Ca atoms and sympathetically cooled molecular ions and nonlaser cooled atomic ions. While much work has been performed on understanding the effect of electronic excitation on ionneutral processes, such as chargeexchange collisions, comparatively less work has been dedicated to understanding how these processes depend on the collision energy of the system. We find collision energy can profoundly impact the outcomes of atomion reactions. In particular, we find that when the collision timescale approaches that of the spontaneous emission timescale of the neutral atom, certain reactions can be suppressed. We also explore how this suppression effect can be reversed through laser control. We also develop a method for controlling atomion collision energy by manipulating the axial equilibrium position of the ion in the LQT, demonstrating order of magnitude increases in energy resolution over alternative techniques. We also detail recent work on the synthesis of the first mixed hypermetallic oxide from reaction of a BaOCH$_{\mathrm{3}}^{\mathrm{+}}$ molecule with a triplet Ca atom. [Preview Abstract] 

E01.00030: A gas cell experiment for charge exchange cross sections with highly charged ions Steven Bromley, Daniel Fox, Chad Sosolik, Jim Harriss, Joan Marler Observations of xrays from highly charged ions in astrophysical plasmas motivates the study of these systems in the laboratory. The dominant process involving highly charged ions is charge exchange between the ion and neutrals. We present a gas cell experiment, optimized for experiments with highly charged ions, for measuring the total charge exchange cross sections for velocityresolved ion beams interacting with neutrals. Preliminary results with $\textrm{Ar}^+$ beams interacting with neutral Ar are consistent with published results. We extend the study to measure the scaling of the crosssections for 1  5 keV $\textrm{Ne}^{q+}$, $\textrm{Ar}^{q+}$, and $\textrm{Kr}^{q+}$ (q = 1) beams interacting with neutral atoms and molecular nitrogen. Further work will investigate the scaling of the cross sections with target atomic number Z for multicharged noble gas ions interacting with neutrals. [Preview Abstract] 

E01.00031: Influence of Combination and Overtone Vibrations on Resonant Positron Annihilation Spectra. G. F. Gribakin, J. F. Stanton, J. R. Danielson, M. R. Natisin, C. M. Surko Lowenergy annihilation spectra of positrons on molecules are typically dominated by positron capture in vibrational Feshbach resonances (VFR) of dipolecoupled fundamental modes.\footnote{Gribakin and Lee, Phys. Rev. Lett. {\bf 97}, 193201 (2006).} However, anharmonic effects can lead to a coupling of the fundamentals to multiquantum excitations (e.g., combinations and overtones) that lead to the enhancement or suppression of the VFR.\footnote{Gribakin, et. al, Phys. Rev. A {\bf 96}, 062709 (2017).} Further, in most molecules there is a broad spectrum of enhanced annihilation between the fundamentals, presumably due to directly excited combination and overtones, where the vibrational density is typically too high to identify discrete modes. An extension of the GribakinLee theory, using the calculated anharmonic vibrational spectra and dipole transition amplitudes for vibrations containing up to 3 quanta, is compared to experiments for several small molecules. This work demonstrates the effects of vibrational anharmonicity and the importance of including higher order couplings. Prospects for the use of a new highresolution positron beam for the meaurement of VFR's due to individual multimodes will be described. [Preview Abstract] 

E01.00032: Positronium scattering from hydrogen and helium atoms at low energies J.Y. Zhang, M.S. Wu, Y. Qian, X. Gao, K. Varga, Z.C. Yan, U. Schwingenschlogl We investigate the elastic scattering of PsH and PsHe below the Ps($n=2$) excitation threshold using the confined variational method with explicitly correlated Gaussians as basis functions. As an extension of the previous work (EPL, $\textbf{99}$ 43001 (2012)), we calculate phase shifts for the elastic PsH scattering for partial waves $1 \leq \ell \leq 3$. We expect that the PsH calculation is to determine the contribution of the mixed symmetry terms to phase shifts for partial waves $\ell > 2$ and to resolve the convergence problems that occur in the calculations of Woods et al. for $^{1,3}\!D$ with the Smatrix complex Kohn variational method (PRA $\textbf{92}$ 022713 (2015)). For the PsHe scattering below the excitation threshold of Ps($n = 2$), we compute phase shifts, pickoff annihilation rates, and momentumtransfer cross sections for partial waves $\ell \leq 3$ to resolve the huge discrepancies between theory and experiment. [Preview Abstract] 

E01.00033: A screened independent atom model for the description of ion collisions from atomic and molecular clusters Tom Kirchner, Marko Horbatsch, Hans J\"urgen L\"udde The recently introduced independent atom model (IAM) pixel counting method (PCM) is used to calculate electron removal cross sections for proton collisions from carbon, water, and argon clusters, i.e., for target species that range from covalently bound to van der Waals systems. The IAMPCM is based on a geometric interpretation of the cross section of a multicenter Coulomb target as a sum of overlapping atomic cross sections [1]. The atomic calculations are carried out using the twocenter basis generator method on the level of a noresponse independent electron description. The screening coefficients in the IAMPCM cross section formula are obtained by counting the visible pixels that represent a given atom in the structure of overlapping circular disks which is obtained when superimposing the atomic cross sections for a given collision geometry. Results for net electron transfer and ionization will be presented for impact energies ranging from 10 to 1000 keV. It will be demonstrated that the cross sections for each cluster species $(X)_n$ show a characteristic dependence on $n$. [1] H.J. L\"udde {\it et al}., Eur. Phys. J. D {\bf 70}, 82 (2016). [Preview Abstract] 

E01.00034: DipoleForbidden Transitions in Numerical Solutions of the TimeDependent Schr\"odinger Equation Dustin Ursrey, Brett Esry Theoretical studies of atoms and molecules in intense, ultrafast laser pulses require numerical solutions of the timedependent Schr\”odinger equation (TDSE). Such numerical solutions necessarily introduce approximations to the exact wavefunction, and – if care is not taken –, these approximations can produce results that do not accurately describe the physics predicted by the TDSE. Here we present one such nonphysical result that can occur in numerical solutions. Specifically, we show that seemingly dipoleforbidden transitions can be found for dissociation of D$_{2}^{+}$, excitation of a hydrogen atom, and excitation of a model three¬level system. Moreover, we show that these nonphysical excitations occur for a variety of spatial representations of the wavefunction (both finitedifferencing and a finiteelement discrete variable representation) and time propagation techniques (CrankNicholson and RungeKutta). We show that these nonphysical excitations are caused by the way electric field is turned on in the code, and propose methods for eliminating such excitations without increasing the computation time required to solve the TDSE. [Preview Abstract] 

E01.00035: Longrange RydbergRydberg interactions at veryhigh $n$ R G Fields, R Brienza, F B Dunning, S Yoshida, J Burgdörfer Excitation of veryhigh$n$ strontium Rydberg atoms under blockade conditions in an atomic beam provides an opportunity to study stronglycoupled RydbergRydberg systems under controlled conditions. ~In the present work, blockade is exploited to create a string of Rydberg atoms with approximately equal initial separations. ~Sudden application of an electric field ``step'' is then used to create Stark wave packets whose subsequent time evolution is monitored through ionization induced by a pulsed electric field. ~Measurements of the number of surviving Rydberg atoms reveal pronounced Stark quantum beats. Preliminary comparisons of the quantum beat behavior for single and multiple Rydberg atoms indicate that RydbergRydberg interactions lead to dephasing and a reduction in the amplitude of the (collective) beats. ~The mechanisms responsible for this are being examined through further experimental studies and through theoretical analysis. [Preview Abstract] 

E01.00036: Controlling strongfield isomerization of acetylene ions Bethany jochim, Ben Berry, T. Severt, Peyman Feizollah, M. Zohrabi, K. J. Betsch, Kanaka Raju P., K. D. Carnes, I. BenItzhak, E. Wells The topic of hydrogen migration in hydrocarbons has garnered considerable attention in recent years in the strongfield community and beyond. Employing coincidence 3D momentum imaging, we study the intense ultrafast laserinduced isomerization and dissociation dynamics of keV ion beams of acetylene, one of the simplest hydrocarbons. Targets of interest include C$_2$H$_2^$, C$_2$H$_2^+$, and C$_2$H$_2^{2+}$, for which we focus on twobody acetylene (CH$^{q_1}$+CH$^{q_2}$) and vinylidene (C$^{q_1}$+CH$_2^{q_2}$) breakup. Laser parameters such as intensity, wavelength, pulse duration, etc., that serve as control knobs for manipulating outcomes such as the kinetic energy release (KER), angular distributions, and branching ratios will be discussed. Moreover, the dependence of these outcomes on the initial ion species will be explored. [Preview Abstract] 

E01.00037: Modeling frustrated tunnel ionization experiments P.T. Johnson, B.A. deHarak, R.D. Glover, D. Chetty, A.J. Palmer, I.V. Litvinyuk, R.T. Sang The fact that an electron can tunnel out of the potential well of its parent atom or molecule in the presence of a strong laser field is the basis of a number of strongfield phenomena such as above threshold ionization, and nonsequential multiple ionization. In both of those cases the parent is left in an ionized state. However, there is a chance that after the electron has tunneled it will return to a bound state  a process known as frustrated tunnel ionization (FTI)~[Nubbemeyer, T., et al. Phys. Rev. Lett. 101(23): 233001 (2008)]. Here we present calculations of FTI yield for argon under various experimental conditions using the rescattering model~[P.B. Corkum, Phys. Rev. Lett. 71, 1994 (1993)] with the addition of a coulomb potential term when dealing with the ``free'' electron. We will contrast the use of different coulomb potential terms and compare these calculations to some of our recently obtained experimental results in both the fewcycle and multicycle regime. [Preview Abstract] 

E01.00038: Modelling highharmonic generation in solids beyond the single active electron Helena Dr\"ueke, Dieter Bauer Laserdriven electrons in linear chains of ions constitute the simplest models for the study of highharmonic generation (HHG) in solids. The importance of band structure, finitesize or surface effects, and electronelectron interaction can be systematically investigated using such models. On the poster, we illustrate our implementation of a timedependent KohnSham solver for the study of solid slabs in intense laser fields. In particular, we present HHG spectra, discuss their cutoffs, and analyze the role of electronelectron interaction and topological surface effects [1,2]. \\ \mbox{\qquad}\\ \noindent {[1]} Kenneth K. Hansen, Tobias Deffge, Dieter Bauer, "Highorder harmonic generation in solid slabs beyond the singleactiveelectron approximation", Phys. Rev. A 96, 053418 (2017).\\ {[2]} Dieter Bauer, Kenneth K. Hansen, "Highharmonic generation in solids with and without topological edge states", (submitted) arXiv:1711.05783. [Preview Abstract] 

E01.00039: ExactExchange Optimized Effective Potential and Memory Effect in Timedependent Density Functional theory ShengLun Liao, TakSan Ho, Herschel Rabitz, ShihI Chu Nowadays, timedependent density functional theory (TDDFT) is an efficient and accurate theoretical method to explore the ultrafast manyelectron dynamic of atomic and molecular systems. However, most of TDDDT applications are limited to the adiabatic approximation, of which the important memory effect is neglected. To go beyond the adiabatic approximation, we derive a SturmLiouvilletype timelocal TDOEP equation for the construction of memorydependent exchangecorrelation (xc) potential associated with orbitaldependent functionals [1]. The nonadiabatic calculations for a onedimensional twoelectron Helium model are performed by using the timelocal TDOEP equation with the exact exchange functional. The timedependent dipole moment and probability density show that the TDOEP approach is more accurate than the KriegerLiIafrate (KLI) approximation and the adiabatic local spin density approximation. In particular, the nonadiabatic and memorydependent terms in the timelocal TDOEP equation describe the timedependent structure of xc potential properly. [1] S.L. Liao, T.S. Ho, H. Rabitz, and S.I. Chu, Phys. Rev. Lett. 118, 243001 (2017). [Preview Abstract] 

E01.00040: Thicknessdependent attosecond streaking time delays in photoemission from magnesium adsorbate layers Qing Liao, Kai Liu, Meiyan Qin, Peixiang Lu, Uwe Thumm We analyze the filmthickness dependence of streaking time delays that are accumulated during photoelectron emission from magnesium valence band (VB) and 2$p$ corelevel (CL) states. Our quantummechanical model [1] predicts that streaked photoemission time delays of VB photoelectrons are almost independent of the film thickness, while those of 2$p$ CL photoelectrons are sensitive to the film thickness below \textasciitilde 100 monolayers (MLs) and increase by \textasciitilde 20 attoseconds as the thickness grows from 20 to 200 MLs [2]. We attribute the different streakingtimedelay dependence on the film thickness for VB and 2$p$ CL photoemission to different degrees of wavefunction localization of the initial bulk and surface states. [1] Q. Liao and U. Thumm, Phys. Rev. Lett. \textbf{112}, 023602 (2014); Phys. Rev. A \textbf{89}, 033849 (2014); Phys. Rev. A \textbf{92}, 031401(R) (2015). [2] Q. Liao, K. Liu, M. Qin, P. Lu, and U. Thumm, submitted. [Preview Abstract] 

E01.00041: A Perturbative Approach to Attosecond Transient Absorption C Cariker, T Kjellsson Lindblom, E Lindroth, L Argenti We present theoretical predictions for the dipolar response of a prototype atom ionized by a weak extremeultraviolet pump pulse and dressed by a moderately strong infrared pulse. The results are obtained with a finitepulse resonant analytical model based on a thirdorder perturbative expansion of the lightatom interaction and on a Fano representation for the resonant continuum. Here the model is used to study how the frequency, timedelay, polarization, and spectral width of the external fields affect the resonant attosecond transient absorption spectra. It is shown that, within the assumptions of the model, only transitions involving intermediate resonant states can in fact alter the absorption spectrum as a function of the delay between pump and dressing pulse. The model predictions are compared with \emph{abinitio} calculations for realistic atoms, obtained by solving numerically the timedependent Schr\"odinger equation in a multichannel closecoupling basis [1]. [1] L Argenti and E Lindroth, Phys. Rev. Lett. 105, 053002 (2010). [2] T Carette et al., Phys. Rev. A 87, 023420 (2013). [Preview Abstract] 

E01.00042: Role of electron correlation in femtosecond relaxation of photoexcited electrons in C$_{\mathrm{60}}$ Mohamed Madjet, Oriol Vendrell, Himadri Chakraborty Electronphonon coupled dynamics in molecules underpins many vital phenomena in matter, including the mobility and collection of carriers in organic devices [1]. Following the absorption of photons by a fullerene molecule, the relaxation of excited electrons to the bandedge via electronphonon (ep) coupling, transferring energy to the vibrational degrees of freedom, is of fundamental interest [2]. We simulate the relaxation dynamics in C$_{\mathrm{60}}$ using two schemes: (i) Quantum Espresso software to describe the structure and the PYXAID package, which employs classical trajectory surface hopping for nonadiabatic (NA) ep coupling [3], to describe the dynamics; this is effectively a single particle frame. (ii) Electronic structure calculated with the package GAMESS, describing the ground state at the HartreeFock level and the excited states at the Configuration Interaction Singles (CIS) level, followed by surfacehopping NA dynamics using Chemical Dynamics Tool Kit [4]. Comparisons indicate a dramatically faster decay induced by correlations. Such ab initio results will motivate and complement femtosecond measurements of relaxation processes in fullerenes via RABITT and streaking approaches. [1] Coropceanu et al, Chem. Rev. \textbf{107}, 926 (2007); [2] Ross et al, Nature Materials \textbf{8}, 208 (2009); [3] Madjet et al, Phys. Chem. Chem. Phys. \textbf{18}, 5219 (2016); [4] Madjet et al., J. Chem. Phys. \textbf{138}, 094311 (2013). [Preview Abstract] 

E01.00043: Correlationinduced time delay in atomic photoionization D. K. Keating, S. T. Manson, V. K. Dolmatov, P. C. Deshmukh, F. Naseem, A. S. Kheifets A study of attosecond time delay of the outer shells of noble gas atoms in the vicinity of innershell thresholds using both relativisticrandomphase approximation (RRPA) and randomphase approximation with exchange (RPAE) methodologies has been performed. The results show that correlation in the form of interchannel coupling engenders significant time delays in the outershell photoemission above each innershell threshold which demonstrates the importance of manybody interactions and wave functions in the understanding of photoelectron dynamics. Without the interchannel coupling, the outershell time delays are essentially zero at the inner shell thresholds, but the coupling induces delays as large as 30 as. Furthermore, while the delays decrease in magnitude above the innershell thresholds, they persist for tens of eV above the thresholds In addition, a lowestorder perturbation theory model is introduced to help understand the phenomenology. [Preview Abstract] 

E01.00044: Angledependent ionization time delay in the neon 2s$\to $\textbf{np resonance series} S. Banerjee, P. C. Deshmukh, V. K. Dolmatov, A. S. Kheifets, S. T. Manson Time delay in photoionization has acquired much attention of the research community and this field has developed very rapidly in the past decade [1, 2]. The interference between more than one ionization channels from the same initial state gives rise to the angular dependence of photoemission time delay [3]. The timedelay of the Ne 2s $\to $ np resonances using the relativisticrandomphase approximation (RRPA) [4] and the relativistic multichannel quantum defect theory (RMQDT) [5] formalisms have been studied recently [6] and dramatic variations were found across each resonance profile with both positive and negative time delay exhibited across each resonance. Using the same methodology, the present study explores the angular dependence of time delay in the region of the resonances. [1] M Schultze \textit{et al}, \textit{Science} \textbf{328}, 1658 (2010). [2] K Kl\"{u}nder \textit{et al, PRL} \textbf{106}, 143002 (2011). \quad [3] A Kheifets et al, \textit{Phys. Rev. A} \textbf{94}, 013423 (2016) [4] W. R. Johnson, C. D. Lin, \textit{Phys. Rev. A} \textbf{20}, 964 (1979) [5] C. M. Lee, W. R. Johnson, \textit{Phys. Rev. A} \textbf{22}, 979. [6] P. C. Deshmukh, A. Kumar, H. R. Varma, S. Banerjee, S. T. Manson, V. K. Dolmatov, A. S. Kheifets (submitted). [Preview Abstract] 

E01.00045: MicroFocused Pink Beam For TimeResolved XRay Emission Spectroscopy MingFeng Tu, Andre Al Haddad, Gilles Doumy, Stephen Southworth, Anne Marie March, Yoshiaki Kumagai, Donald Walko, Linda Young, Christoph Bostedt Xray emission spectra (XES) in the valencetocore (vtc) region offer direct information on occupied valence orbitals. They emerge as a powerful tool for the ligand identification, bond length, and structural characterization. However, the vtc feature is typically two orders of magnitude weaker than $K$$\alpha$ emission lines, making it hard to collect, especially for transient species. To overcome the difficulty, pink beam excitation capability was demonstrated recently at Sector 7 of the Advanced Photon Source. A watercooled flat mirror rejects higher harmonics, and beryllium compound refractive lenses (CRLs) focus the reflected fundamental beam (pink beam) to a 40$\mu$$m$ x 10$\mu$$m$ elliptical spot at sample target that matches the laser spot size used for photoexcitation. With an Xray flux of 10$^{15}$ photons per second, nonresonant XES spectra were taken on iron(II) ferrocyanide and on photoexcited iron(II) tris(2, 2$^{'}$bipyridine). We could reproduce previous measurements with only a fraction of the acquisition time, demonstrating the ability to measure high quality spectra of low concentration species. [Preview Abstract] 

E01.00046: Time Resolved 3D momentum imaging of Molecular Dynamics with VUV pulse pairs Maya Fabrikant, Kirk Larsen, Tahiyat Rahman, Daniel Slaughter, Thorsten Weber We report progress on an apparatus for running UVVUV pumpprobe experiments with Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) for investigating ultrafast dynamics in polyatomic molecules upon VUV excitation. We loosely focus a highpower 400 nm pulsed laser into an argon filled 10 cm long gas cell to create a highflux, coherent third harmonic (133nm) photon beam (10$^{\mathrm{9}}$ photons/shot) via High Harmonic Generation (HHG). A custom, invacuum splitmirror interferometer creates VUV  VUV/UV pulse pairs for pumpprobe studies with a relative delay range up to several picoseconds, and 170 as resolution. In the experimental endstation, the beam is backfocused into a supersonic jet by a spherical mirror at the exit of a COLTRIMS spectrometer, which measures the 3D momenta of charged particles that are produced. [Preview Abstract] 

E01.00047: Photoion and photoelectron spectroscopy applied for in situ characterization of femtosecond XUV pulses S.J. Robatjazi, S. Pathak, Kanaka Raju P., J. Powell, W.L. Pearson, D. Rolles, A. Rudenko Accurate knowledge of the pulse duration and temporal structure of extremeultraviolet (XUV) pulses is crucial for timeresolved experiments employing freeelectron lasers like FLASH, SCSS and FERMI, or light sources based on highharmonic generation (HHG). Since alloptical techniques are typically challenging for the XUV domain, ionizationbased methods are often employed for XUV pulse characterization. Here we report on a comparative study of temporal properties of femtosecond HHG pulses in a broad photon energy range (from 17 to 100 eV) performed using photoion and photoelectron spectra obtained in the XUV pump  nearinfrared (NIR) probe experiments. For lower photon energies, the XUV pulse duration and the exact position of the temporal overlap between the XUV and NIR pulses can be retrieved from the delaydependent doubletosingle ionization ratios for Xe atoms or CO$_{\mathrm{2}}$ molecules, whereas for higher energies, the ratio of Xe$^{\mathrm{3+}}$ to Xe$^{\mathrm{2+}}$ ion yields after innershell (Xe 4d) photoabsorption can be exploited. We compare the results obtained using these schemes to the outcome of electron sideband measurements, and discuss applications of this setup to photoionphotoelectron coincidence experiments. [Preview Abstract] 

E01.00048: Coherent control of CO\(_2\) bending vibration with phaselocked twinpeaked pulses David B. Foote, GuanYeu Chen, Jane Lee, Hyounguk Jang, Wendell T. Hill, III Other than the simplest cases, the mechanisms by which an optimal control pulse (OCP) guides a target system to its final state are generally not intuitive. Attempts to deconstruct these OCPs by isolating dominant pulse features have had limited success. We have previously found OCPs, consisting of phaselocked pulse trains as a dominant feature, that maximized CO\(_2\) bending vibration during strong field Coulomb explosion. Beyond the dominant feature, the OCPs also contained smaller features (e.g., satellite pulses, pedestals), which had an unknown effect on the bending dynamics. In light of this observation, we studied the CO\(_2\) bending response to a pair of pulses with variable interpeak delay \(\tau\) and relative phase \(\Delta \phi\). Each peak was \(\sim 70\) fs duration with an intensity of \(\sim 9\times10^{14}\) W/cm\(^2\). We observed changes in the bending amplitude by changing both \(\tau\) and \(\Delta \phi\); the bending was smaller, however, than the bending induced by the OCPs. In this presentation, we will discuss the mechanisms by which the relative phase and delay of a twinpeak pulse can change the bending response, as well as the role that more subtle features play in controlling the dynamics. [Preview Abstract] 

E01.00049: Intrashell coherent population transfer among degenerate Rydberg states Daniel Vrinceanu Quantum computing with high angular momentum Rydberg states is advantageous because of the strong interaction permitted by the enormous electric dipole moments of these states, and also because these states have long radiative lifetimes. However, Rydberg states are accessible only from the ground state, in transitions to low angular momentum states. Based on the exact analytical solution for the dynamics of degenerate states within the Rydberg shell, I investigate ways to design electric pulse shapes that can facilitate coherent population transfers. Examples of low to high angular momentum transfer of Rydberg states are discussed. [Preview Abstract] 

E01.00050: Transient core structural dynamics at the solidtoplasma transition of the cluster Yoshiaki Kumagai, Akinobu Niouzu, Phay Ho, Toshiyuki Nishiyama, Naomichi Yokono, Hironobu Fukuzawa, Tsukasa Takanashi , Daehyun You, Taishi Ono, Shigeki Owada, Ichiro Inoue, Akira Kon, Kensuke Tono, Makina Yabashi, Linda Young, Kiyoshi Ueda, Kiyonobu Nagaya, Christoph Bostedt We have conducted an xray/xray pump/probe experiment to study transient nuclear dynamics upon strong electronic excitation in nanoclusters with Angstrom resolution. We employed twocolor hard xray scattering with well separated energies and well characterized arrivaltimes at the SACLA freeelectron laser. The first xray pulse is used to characterize the size and orientation of the vanderWalls nanocrystals as well as to induce the xray ionization and expansion processes in a nanoparticle. The second pulse is used to probe the nuclear dynamics following the strong ionization. Using the exact same Bragg reflection from two different color xray pulses yields unprecedented information about the nanoparticle lattice response upon ionization, not accessible in previous experiments [K. Ferguson et al, Sci. Adv. 2, 1500837 (2016)]. [Preview Abstract] 

E01.00051: Optically pumped semiconductor lasers for atomic and molecular physics Shaun C. Burd, JussiPekka Penttinen, Andrew C. Wilson, David T. C. Allcock, Daniel H. Slichter, Raghavendra Srinivas, Mircea Guina, Dietrich Leibfried, David J. Wineland Experiments in atomic, molecular, and optical (AMO) physics rely on lasers at many different wavelengths and with varying requirements on spectral linewidth, power, and intensity stability. Optically pumped semiconductor lasers (OPSLs), when combined with nonlinear frequency conversion, can potentially replace many of the laser systems currently in use. We present singlefrequency OPSL systems developed by our group for use in photoionization of neutral magnesium atoms and also for laser cooling and quantum state manipulation of trapped $^{25}$Mg$^+$ ions. We also report progress on developing OPSLs to perform these tasks for $^9$Be$^+$ ions. Our OPSL systems serve as prototypes for applications in AMO requiring singlefrequency, powerscalable laser sources at multiple wavelengths. [Preview Abstract] 

E01.00052: Quantum interference between autonomous singlephoton sources from Dopplerbroadened atomic ensembles Han Seb Moon, Taek Jeong, Jiho Park, Heonoh Kim To realize a quantum network based on quantum entanglement swapping, bright and completely autonomous singlephoton sources are essentially required. They experimentally demonstrate HongOuMandel quantum interference between two independent bright photonpair sources to show the indistinguishability and purity in Dopplerbroadened warm Rb atomic vapor. The manuscript describes bright autonomous singlephoton sources based on the hot vapor cells that can work continuously and greatly simplifies the experiment. It might be an important step towards the scalable quantum network. [Preview Abstract] 

E01.00053: Study of Preparation and Measurement of Spatial Modes of Light in Different Bases Nathaniel Ristoff, F. Elohim Becerra Transmission of light carrying information in the transverse profile of the field through multimode fibers can provide a path for increasing capacity in communications and for distributing high dimensional entanglement. However, cross talk between spatial modes in the fiber makes maintaining and retrieving the encoded information challenging. Moreover, while the selection of encoding basis for these spatial modes is arbitrary, there may be particular bases that are preferred for different processes generating correlated photons. We investigate a method previously used to characterize fewmode fibers to study the preparation and measurement of light with many spatial modes.~ We study the differences between Laguerre (LG) and Hermite (HG) Gauss modes for encoding information and investigate the potential of this method to reverse intermodal crosstalk in optical fibers. [Preview Abstract] 

E01.00054: Toward a precision force sensor based on Bloch oscillations of atoms in an optical lattice Robert Niederriter, Chandler Schlupf, Kayla Rodriguez, Paul Hamilton Precision force sensors have potential for exploring and constraining unknown forces such as dark energy candidates [1]. We are developing a precision sensor that measures the force on ytterbium atoms optically trapped inside an optical cavity. The trapped and cooled atoms undergo Bloch oscillations which can be monitored for continuous force measurement [2]. Using trapped atoms allows long measurement times in a small volume. Continuous measurement enables detection of timevarying forces and reduces sensitivity to vibrations. The atoms for the force sensor are cooled and trapped in a magnetooptical trap (MOT) overlapping the TEM00 mode of an optical cavity, and then suspended in the optical lattice of the cavity after the MOT is turned off. We present progress towards the development of a precision force sensor and tests of new fundamental forces. [1] P. Hamilton, M. Jaffe, P. Haslinger, Q. Simmons, H. Müller, J. Khoury, Science 349, 849 (2015). [2] B. Prasanna Venkatesh, M. Trupke, E. A. Hinds, and D. H. J. O'Dell, Phys. Rev. A 80, 063834 (2009). [Preview Abstract] 

E01.00055: Accurate Electron Spin Optical Polarimetry (AESOP) Keith Foreman, Timothy Gay Third generation parityviolation experiments involving highenergy longitudinally polarized electron scattering require determination of the electron beam polarization to unprecedented accuracy [1]. We are developing a new method to improve polarimetry for such beams based on polarized electron impact excitation of noblegas targets [2]. A crucial requirement of this technology (``accurate electron spin optical polarimetry'' (AESOP)) is the ability to measure optical polarization to an accuracy of 0.1{\%} of the Stokes parameter values. We report recent progress towards achieving optical polarization measurements to this level of accuracy. Using both a laserbased tabletop optical polarimeter and TracePro [3] raytracing software, we have identified several unexpectedly large (\textasciitilde 0.5{\%}) sources of error associated with reflections and spurious temperature variations. The mechanisms by which they contribute to the polarimetry measurement, how the errors are correlated, and the relative magnitude of the contribution of each error, as well as error mitigation methods, are discussed. 1) E. Chudakov, AIP Conf. Proc. 1563, 29 (2013). 2) T. J. Gay, J. E. Furst, K. W. Trantham, and W. M. K. P. Wijayaratna, Phys. Rev. A 53, 1623 (1996). 3) TracePro Expert version 7.8.4, Lambda Research Corporation, Littleton, MA, USA [Preview Abstract] 

E01.00056: Precision sensing and hybrid optomechanics with opticallylevitated nanoparticles Cris Montoya, Gambhir Ranjit, Evan Weisman, Chethn Galla, Andrew Geraci The large mechanical quality factor of optically levitated dielectric particles makes them a promising tool for precision measurement experiments. We describe progress on using nanospheres as a tool to study the Newtonian gravitational inverse square law at micron length scales where we have achieved zeptonewton force sensitivity. Furthermore, cooling the vibrational modes of the particles to the ground state can be used to test the limits of quantum mechanics in macroscopic objects, and in matterwave interferometry experiments. We also describe experimental progress on sympathetically cooling levitated nanospheres using cold atoms. In this setup, an optical lattice couples the atoms to the levitated sphere through radiation pressure forces. We have shown theoretically that ground state cooling of the spheres is possible using this approach. [Preview Abstract] 

E01.00057: Development of Nondestructive SingleMolecule Spectroscopy Utilizing Photon Recoil Readout James Dragan, Mark Kokish, Greg\'{o}rio Moreira da Silva, Qiming Wu, Vincent Carrat, Brian Odom The complex structure of molecules can be used in developing technologies for quantum sensing, quantum chemistry and precision measurements. To achieve this, control of the external and internal degrees of freedom of the molecule are necessary. Having previously demonstrated rovibrational ground state preparation of aluminum monohydride (AlH$^+$)\footnote{Lien, C.Y. et al, Nat. Commun. 5:4783 (2014)} we now aim to implement an experiment to perform nondestructive state readout of AlH$^+$. Adapting the technique of quantum logic spectroscopy, the internal state of AlH$^+$ can be mapped onto the motional state of a cotrapped atomic ion, where state readout is convenient. To induce motion on the atomic ion, we drive repeated molecular photon recoil events using a broadband laser, whose excitation is dependent on the molecule being in its ground vibrational state. We can then accomplish nondestructive rovibrational spectroscopy of the molecular ion by driving transitions to metastable vibrational excited states. With the tools of state preparation, state readout and spectroscopy in hand our experiment aims to achieve coherent control and study of the AlH$^+$ molecule. [Preview Abstract] 

E01.00058: Measurement of the Fine Structure Constant as a Test of the Standard Model Richard Parker, Chenghui Yu, Weicheng Zhong, Joyce Kwan, Brian Estey, Holger Muller Measurements of the fine structure constant $\alpha $, using methods from atomic, condensedmatter, and particle physics, are powerful tests of the overall consistency of theory and experiment across physics. We have measured $\alpha \quad =$ 1/137.035999046(27), at 2.0\texttimes 1010 accuracy, via the recoil frequency of cesium133 atoms in a matterwave interferometer. We used multiphoton interactions such as Bragg diffraction and Bloch oscillations to increase the phase difference for the interferometer to over 12 million radians, which reduced the statistical uncertainty and enabled control of systematic effects at the 0.12 partperbillion level. This is an unprecedented test of the standard model of particle physics, being the first direct measurement of $\alpha $ with an error below the 5th order quantum electrodynamics contribution in the electron's gyromagnetic anomaly. It also has implications for the unexplained anomaly of the muon's magnetic moment, and strongly constrains multiple dark sector candidates as well as substructure of the electron. [Preview Abstract] 

E01.00059: Demonstration of enhanced spectral broadening of frequency combs for astrocombs used in Earthlike exoplanet searches Aakash Ravi, David Phillips, Nicholas Langellier, Timothy Milbourne, Maya Miklos, Ronald Walsworth One technique for detecting exoplanets (i.e. planets outside our solar system) is the radial velocity method. This technique works by observing, in a starexoplanet system, the periodic shifts in the star’s spectral lines caused by the gravitational influence of an orbiting planet. Detecting Earthmass planets around Sunlike stars is very challenging, requiring extremely precise calibration the of astrophysical spectrographs used to make such measurements. To address this challenge, we employ a visible wavelength laser frequency comb as a wavelength calibration source. Our calibrator, known as an astrocomb, is realized by spectrally broadening and shifting the output of a 1 GHz repetition rate modelocked Ti:sapphire laser using a photonic crystal fiber and then filtering the comb lines to create a coarsetoothed comb with 16 GHz line spacing. Our astrocomb system has been implemented at the TNG telescope on La Palma, Spain to calibrate the HARPSN spectrograph. Here, we present several enhancements to the spectral broadening component which we are fabricating for use with a fully automated Ti:Sapphire laser. We also present ongoing combcalibrated astrophysical measurements, including measurements of solar spectra using a compact solar telescope. [Preview Abstract] 

E01.00060: Spectroscopy of a solidstate optical clock transition Mohit Verma, Hiromitsu Sawaoka, Amar Vutha Rare earth ions doped into solidstate host crystals exhibit optical transitions with long coherence times, making them useful for applications such as quantum memories. However, optical transitions in these systems are typically inhomogeneously broadened into $\sim$GHzbroad bands, which limits their utility as absolute frequency references for atomic clocks. We have identified the highly forbidden $~^7F_0 \to ~^5D_0$ transition in Sm:SrF2 as a possible exception to this general rule, with very weak coupling to the crystal environment. We report the first direct laser excitation of this highly forbidden transition, and the observation of an excited state lifetime exceeding 10 ms. This system could lead the way to solidstate optical atomic clocks that do not require laser cooling and trapping. [Preview Abstract] 

E01.00061: Placed in static magnetic fields, Permalloy (mumetal) shields produce timevarying magnetic fields. Benedict Feinberg, Harvey Gould Delayed changes in magnetization cause the magnetic field inside a Permalloy shielded volume to decrease by approximately 20 percent over hours to days. The shields tested were 3 mm thick 25 and 30 cm diameter HyMu ``80''$^{\mathrm{TM} },$ cylinders, with and without end caps. They were demagnetized and then subjected to a uniform, constant, external magnetic field of 0.48 A/m to 16 A/m, the latter being comparable to the Earth's magnetic field at its weakest point. This effect has implications for precision measurements where constant magnetic fields are needed. Further details may be found at www.eedm.info. [Preview Abstract] 

E01.00062: Magnetometry based on a levitated ferromagnetic particle Tao Wang, Metin Kayci, Sean O’ Kelley, Derek Kimball, Sean Lourette, Alexander Sushkov, Alexander Wilzewski, Dmitry Budker A “magnetometer” based on a magnetized ferromagnetic microparticle levitated over a superconductor is demonstrated. The particle is placed inside a well in the superconductor; when the superconductor is cooled below the critical temperature with liquid helium, the particle is levitated as a consequence of the Meissner effect. The levitated particle is isolated from molecular collisions at the cryogenic temperatures and partially shielded from external magnetic fields because the superconductor used for levitation acts as magnetic shield which is free of Johnson noise, with a shielding factor better than $5\times 10^6$. When external magnetic field is applied to the system, the particle only feels a small residual field determined by the geometry of the experiment. The motion of the particle is recorded with a camera. The residual magnetic field is determined by measuring the frequencies of the particle’s motion. Such a “magnetometer” may be useful for measurement of, for example, exotic spindependent interactions of electrons. [Preview Abstract] 

E01.00063: A singlebeam, potassium SERF magnetometer for the Global Network of Optical Magnetometers to search for Exotic physics (GNOME) Sunyool Park, Perrin Segura, Seraphina Nix, Jason Stalnaker Ultralight axionlike particles are a possible candidate for dark matter. These particles can result in topological defects that can be detected through their coupling with the spins of elementary particles. This coupling results in a pseudomagnetic interaction. The Global Network of Optical Magnetometers to search for Exotic physics (GNOME) searches for transient signals caused by the Earth going through these topological defects using several magnetometers located throughout the world to differentiate true signals from false positives. At Oberlin College, we are developing a singlebeam spin exchange relaxationfree (SERF) magnetometer using potassium atoms with a helium buffer gas. We monitor the absorption of circular polarized light going through the vapor cell housed within four layered magnetic shields. The magnetic field dependence of the absorption is used to measure the magnetic field. We also discuss future plans to construct a RbK$^3$He SERF comagnetometer to achieve better sensitivity. [Preview Abstract] 

E01.00064: RF imaging with NV centers in diamond Pauli Kehayias, Diana Prado Lopes Aude Craik, Ronald Walsworth We use nitrogenvacancy (NV) defect centers in diamond for widefield imaging of radio frequency (RF) magnetic fields from microelectronic sources. Building on our ongoing work using NV centers for imaging static magnetic fields from geological and biological samples, we image magnetic fields with a wide frequency range over a millimeter field of view. We outline ongoing sensitivity and instrumentation improvements and present initial demonstrations measuring fields from simple electronic circuits, validating the measurements with finiteelement simulations. We extend this technique to more sophisticated circuits, for which finiteelement models are nontrivial. [Preview Abstract] 

E01.00065: `Radiation Damping' in Gas Spin Comagnetometers. Zhiguo Wang, Rui Zhang, Hong Guo We report a new kind of interaction between different species spins that appears when at least one species spin is precessing. The induced precession in the other species spin or spins will lead to damping and frequencyshift for the precessing spins. When one species spin is operating in a FID mode, its transverse relaxation time and oscillating frequency changes with time due to the influence of the other species spin. When one species spin is operating in selfoscillating mode, its transverse relaxation time and oscillating frequency will also be changed by the other species spin. These effects will influence the accuracy of NMR probes which are widely used in the search for CPT and Lorentzinvariance violation, the fifth force, and so on. If this problem is solved or considered, the limit of the aforesaid search can be improved. [Preview Abstract] 

E01.00066: Collective behavior in the nonequilibrium dynamics of ultracold atoms LiangYing Chih, Athreya Shankar, John Bartolotta, Haonan Liu, Murray Holland A common theme of both ultracold quantum gas physics and cavity QED physics is the central role of the collective atomic behavior in the nonequilibrium dynamics. For example, when atoms with ultranarrow linewidth transitions interact with a lossy cavity mode, the resulting collective behavior may lead to exciting emergent phenomena, such as superradiance and spectrally pure light with a frequency that is insensitive to cavity length fluctuations. We investigate a proposed system consisting of a beam of initially excited ultranarrowlinewidth atoms passing through a lossy cavity which promises to be a practical approach to realize a steadystate superradiant laser. In a different physical setup but with similar underlying dynamical equations, we consider the collective effects in the subDoppler cooling of hundreds of ions in a Penning trap using a laser cooling method based on electromagnetically induced transparency. Finally, we consider the behavior of a condensated quantum gas driven by a periodic modulation of the twobody scattering length in which we observe the collective dynamics to result in the production of pairs of atoms with high momentum that is equal in magnitude but opposite in direction. [Preview Abstract] 

E01.00067: Critical phenomena and the universality of the KibbleZurek mechanism in driven dissipative systems Hil Fung Harry Cheung, Yogesh S Patil, Tamiro Villazon, Aditya G Date, Anushya Chandran, Anatoli Polkovnikov, Mukund Vengalattore Due to the interplay between coherent evolution and dissipation, open quantum systems can exhibit new phases of matter and novel critical behavior that is not captured by the standard classification of equilibrium phase transitions. We experimentally realize a driven dissipative phase transition in an optomechanical system and investigate the validity of the KibbleZurek hypothesis, which relates the nonequilibrium dynamics to the equilibrium behavior. While this hypothesis has been studied in equilibrium phase transitions, we report the first quantitative study of the KibbleZurek hypothesis in a driven dissipative system. Further, we dynamically impose nonMarkovian systembath interactions via continuous measurement and feedback, and find that the critical behavior can be substantially modified with significant changes to the critical exponents, e.g. the critical exponent $\nu z=1.50(9)$ compared to the Markovian exponent $\nu z=1$. We further verify a quantitative scaling law that relates the growth of order as a function of temperature and quench rate that is valid over the entire range of the quench. Our results show that nonequilibrium quench dynamics can be used to extract universal exponents in drive dissipative systems, opening new avenues to study the theoretically challenging cases of systembath interactions and their influence on critical phenomena. [Preview Abstract] 

E01.00068: Measurement of the Stability of PWave Pairs in a Quasi1D Fermi Gas Danyel Cavazos, Tsunglin Yang, Yating Chang, Zhenghao Zhao, Randall G. Hulet $P$wave interactions are known to lead to intriguing quantum phenomena such as $p + ip$ topological superfluids and Majorana fermions. However, the experimental detection of these phenomena in ultracold atomic gases remains a challenge due to the severe atom losses from threebody recombination collisions near the pwave Feshbach resonance in a 3D atomic gas. It has been recently predicted\footnote{Lihong Zhou and Xiaoling Cui, Phys. Rev. A 96, 030701 (2017).} that such effects could be suppressed by introducing 1D confinement, thus leading to the formation of pwave atom pairs. We will study the stability of atom pairs in a quasi1D Fermi gas interacting via a confinementinduced pwave Feshbach resonance. We spinpolarize $^6$Li atoms in one of the lowest hyperfine levels whose pwave interactions are tunable via a Feshbach resonance. Quasi1D confinement is achieved with a twodimensional compensated optical lattice. The stability of the pwave pairs will be evaluated by measuring the atom loss, which can be obtained by comparing the atom number before and after preparing the system near resonance. [Preview Abstract] 

E01.00069: Formation of a MatterWave Breather in a $^7 \mathrm{Li}$ BEC P. Bagge, J. H. V. Nguyen, D. Luo, R. G. Hulet A breather is a nonlinear wave phenomenon that occurs in systems well described by a nonlinear wave equation such as the onedimensional nonlinear Schr\"{o}dinger equation (1D NLSE). It derives its name from its characteristic profile, which is localized in space and oscillates in time. As a solution to the 1D NLSE, the simplest form of a breather is a bound state of two solitons with zero relative velocity. Despite observations of breathers in various physical systems, a matterwave analog has yet to be created. Theory suggests that matterwave breathers may show quantum manybody effects, even for atom numbers in the thousands\footnote{V. A. Yurovsky, B. A. Malomed, R. G. Hulet, and M. Olshanii, Phys. Rev. Lett. 119, 220401 (2017).}. We explore the creation of a matterwave breather by starting with a fundamental bright soliton formed from a $^7 \mathrm{Li}$ BoseEinstein condensate with attractive interactions and confined to a highly elongated, cylindrically symmetric harmonic trap. We use a Feshbach resonance to quench the atomic interaction by a factor of four to induce the formation of a breather with a 3:1 amplitude ratio. We will explore the dissociation of the breather by reflection/transmission at a barrier and its spontaneous dissociation due to quantum effects. [Preview Abstract] 

E01.00070: Correlation Effects in the QuenchInduced Phase Separation Dynamics of a TwoComponent Ultracold Quantum Gas Simeon Mistakidis, Garyfallia Katsimiga, Panayotis Kevrekidis, Peter Schmelcher We explore the quench dynamics of a binary BoseEinstein condensate crossing the miscibilityimmiscibility threshold and vice versa, both within and in particular beyond the meanfield approximation. Increasing the interspecies repulsion leads to the filamentation of the density of each component, involving shorter wavenumbers and longer spatial scales in the manybody approach. These filaments appear to be strongly correlated and exhibit domainwall structures. Following the reverse quench process multiple darkantidark solitary waves are spontaneously generated and subsequently found to decay in the manybody scenario. We simulate singleshot images to connect our findings to possible experimental realizations. Finally, quenches within the miscible and the immiscible regime are discussed. [Preview Abstract] 

E01.00071: Measurements of Collective Mode Frequencies in a Multicomponent Quantum Gas Joshua Hill, James Aman, Thomas Killian The frequencies of collective oscillatory modes provide a powerful probe of manybody physics in ultracold atomic gases. Here, we describe our characterization of collective modes which are excited trapped samples of ultracold strontium. A cold thermalgas of Strontium atoms is prepared in a succession of magnetooptical trap (MOT) stages before being evaporatively cooled in an optical dipole trap (ODT). Additional confinement is then introduced by ramping on a second laser beam, the potential minimum of which is overlapped with the ODT. While maintaining the ODT, the second beam is rapidly turned off, and the gas undergoes collectivemode oscillations. These oscillations are clearly visible in the calculated temperature of the gas after timeofflight absorption imaging. We identify both center of mass (“sloshing”) and quadrupole modes. [Preview Abstract] 

E01.00072: Entanglement induced interactions in binary mixtures Jie Chen, Johannes Schurer, Peter Schmelcher We establish a conceptual framework for the identification and the characterization of induced interactions in binary mixtures and reveal their intricate relation to entanglement between the components or species of the mixture. Exploiting an expansion in terms of the strength of the entanglement among the two species, enables us to deduce an effective singlespecies description. In this way, we naturally incorporate the mutual feedback of the species and obtain induced interactions for both species which are effectively present among the particles of same type. Importantly, our approach incorporates fewbody and inhomogeneous systems extending the scope of induced interactions where two particles interact via a bosonic bathtype environment. Employing the example of a onedimensional spinpolarized ultracold BoseFermi mixture, we obtain induced BoseBose and FermiFermi interactions with shortrange attraction and longrange repulsion. With this, we show how beyond species meanfield physics visible in the twobody correlation functions can be understood via the induced interactions. [Preview Abstract] 

E01.00073: A MOT (MagnetoOptical Trap) created by narrowband lasers. Jianing Han, Lindsay Hutcherson, Gayatri Deshmukh, Morgan Umstead, Andy Hu, Young Lee, Zhanguo Bai Most diode lasers used for creating MagnetoOptical Traps are standing wave lasers. Specifically, a grating is used to reflect the output from a diode laser back into the laser diode to form an external cavity. Typically, the first order diffraction is sent back to the diode laser. In this presentation, we sent the second order diffraction from the grating back to the diode. A MOT is created using this type of lasers. The characterization of the MOT will be presented in this presentation. [Preview Abstract] 

E01.00074: Adiabatic transfer cooling and trapping using narrowline optical and Raman transitions Juan A. Muniz, Baochen Wu, Julia R. K. Cline, Graham P. Greve, Matthew A. Norcia, John P. Bartolotta, Murray J. Holland, James K. Thompson A novel cooling mechanism on narrowlinewidth optical transitions has been recently demonstrated. A set of counterpropagating laser beams are swept in frequency in a sawtooth manner to cause adiabatic LandauZener transfers between an atom’s ground and excited state, while Doppler shifts provide a timeordering that ensures the associated photon recoils oppose the atom's motion. We report progress on using this technique to cool strontium and create a 10 $\mu$K 3D MOT for both bosonic and fermionic isotopes. We also demonstrate subDoppler cooling in rubidium using artificiallynarrow Raman transitions, and we provide a model for extending the technique to other systems without narrow linewidths. Both the experiments and theoretical modeling may find potential applications in cooling molecules or other systems without welldefined cycling transitions or for systems with large inhomogeneous broadening. [Preview Abstract] 

E01.00075: Trapped Ion System for Quantum Simulation with Phonons S. Charles Doret, Ashay Patel Systems of trapped atomic ions can be exquisitely controlled in the laboratory, making them wellsuited for use as the `engine' for emulating quantum phenomena. Our laboratory is working towards using this control to explore quantum simulations with phonons in chains of trapped calcium ions. We are particularly interested in exploring the crossover between ballistic heat transport and diffusive conduction, work relevant to future largescale trapped ion quantum information processors as well as understanding heat flow in nanoscale structures. We present progress working with chains of multiple cotrapped calcium isotopes geared towards two experiments: measuring sympathetic cooling rates and the onset of Fourier's Law thermal gradients, and performing a precision measurement of the isotope shift within the $^2$S$_{1/2} \rightarrow ^2$D$_{5/2}$ electric quadrupole transition in Ca$^+$. [Preview Abstract] 

E01.00076: Toward AllOptical Loading of CoTrapped Be$^+$ and O$_2^+$ Alexander Frenett, Christian Pluchar, Ryan Carollo, David Hanneke Trapped and sympathetically cooled O$_2^+$ ions are a promising system for precision measurements, optical frequency metrology, and searches for new physics. We describe our techniques to load O$_2^+$ along with Be$^+$ coolant ions through resonanceenhanced photoionization. For beryllium, a customdesigned monolithic doubling cavity generates 235 nm light for singlecolor $1+1$ ionization on the $^1S_0 \rightarrow \, ^1P_1$ transition. In O$_2$, a cold molecular beam is photoionized via singlecolor $2+1$ REMPI on the $X \, ^3\Sigma_g^ \rightarrow\rightarrow d \, ^1\Pi_g \rightarrow X \, ^2\Pi_g(\mathrm{O}_2^+)$ transition. This transition is vibrationally selective and loads ions in a small number of rotational states. We describe initial work conducting spectroscopy of the molecular transition and plans for integrating the cold beam into our trap. [Preview Abstract] 

E01.00077: Atom Chip AC Zeeman Potentials: Trapping and Interferometry Andrew Rotunno, Shuangli Du, Andrew Pyle, Seth Aubin We present a largely underused tool in atom chip technology, the AC Zeeman force, which can push, pull, or trap neutral atoms of any spin state using microwave magnetic fields near atomic hyperfine resonances. We evaluate multiple microstrip chip designs for use in atom trapping and interferometry, and evaluate the effects of detuning, state mixing, and the AC Stark effect on the viability of trapping and interferometric schemes. All trapping schemes involve sending multiple microwave currents with tunable power, frequency detuning, and relative phase through atom chip traces, creating a local microwave magnetic nearfield minimum which can target individual spin states, allowing for statespecific trapping and transport. Interferometers based on AC Zeeman traps allow for atom localization, long integration times using trapped atoms, and allow for multimode interferometry of thermal atom clouds. A simpler interferometer scheme involves regions with a linear nearfield gradient in combination with a laser dipole trap. Current work uses ultracold rubidium87 at 6.8 GHz, we also anticipate using potassium isotopes with hyperfine splittings in the .251.3 GHZ range. [Preview Abstract] 

E01.00078: Dark matter detection through molecular excitations Jes\'{u}s P\'{e}rezR\'{i}os, Harikrishnan Ramani, Eden Figueroa, Rouven Essig The existence of dark matter has been confirmed by astrophysical observations, however its nature remains as one of the most intriguing open questions in physics. Over the last few years, the search for dark matter particles has begun to expand to masses below the proton mass (subGeV dark matter). Such dark matter may have a weak interaction with StandardModel particles, which could allow it to be detected through scattering or absorption effects in atomic and molecular systems. In particular, internal degrees of freedom in molecules offer a great scenario for subGeV dark matter detection due to the low energy required to excite these degrees of freedom. Here, we propose a novel platform for detecting subGeV dark matter by detecting the vibrational excitation caused by dark matternucleus scattering on a diatomic gas at low temperature and pressure. As a result, this technique is sensitive to the dark matter in the mass range of 500 keV to 1 GeV, depending on the particular choice of molecular target. [Preview Abstract] 

E01.00079: Toward the measurement of the parity violating transition amplitude and the anapole moment in the cesium ground hyperfine states via twopathway interference. Jungu Choi, George Toh, Nathan Glotzbach, Dan Elliott We present the full characterization of the experimental setup of RFRaman interference in the ground hyperfine states of cesium for precision measurement of the nuclear anapole moment. We have developed an RF open resonator at 9.2 GHz to observe the "weak" atomfield interaction and minimize contributions due to various systematic effects. The simulations and measurements are in good agreement with one another and show good power buildup in the atomfield interaction region. We have developed lasers at 852 nm that are phaselocked to the RF fields to "strongly" excite the same Raman transition between the same hyperfine states for the purpose of enhancing the signaltonoise ratio. We report some preliminary results such as RFoptical interference measurements. [Preview Abstract] 

E01.00080: EDM measurements on cold $^{\mathrm{225}}$Ra and $^{\mathrm{171}}$Yb atoms Tian Xia, Matthew Dietrich, Jaideep Singh, ZhengTian Lu, Michael Bishof, Kevin Bailey, John Greene, Peter Mueller, Thomas O'Connor, Tenzin Rabga, Roy Ready, YuKun Feng, TongYan Xia, Yang Yang, ShaoBo Zhang, Tao Zheng, BaoLong Lv, ZhuanXian Xiong EDM measurements on diamagnetic atoms probe CPviolating effects in the nucleus. Some types of these BeyondStandardModel effects are known to be strongly enhanced in $^{\mathrm{225}}$Ra due to octupole deformation of the nucleus. Other favorable characteristics of $^{\mathrm{225}}$Ra include a high atomic number (Z $=$ 88), a ground state of $^{\mathrm{1}}$S$_{\mathrm{0}}$, and a nuclear spin 1/2. An EDM search is carried out on this radioactive isotope (halflife 15 d) using lasercooled atoms. Meanwhile, $^{\mathrm{171}}$Yb is a stable isotope with atomic properties and transitions similar to those of $^{\mathrm{225}}$Ra, and is particularly useful as a proxy of $^{\mathrm{225}}$Ra for developing laser trapping and probing techniques, for testing various measurement schemes, and for investigating systematic errors. Moreover, $^{\mathrm{171}}$Yb atoms can be placed within 0.1 mm of $^{\mathrm{225}}$Ra, and act as a comagnetometer. A laser trap of Yb atoms is under development towards an EDM measurement. [Preview Abstract] 

E01.00081: $^{\mathrm{207}}$PbF neardegeneracy {\&} BaF microwave global fit Richard Mawhorter, Jose MunozLopez, Yongrak Kim, Andreas Biekert, Trevor Sears, JensUwe Grabow, A.D. Kudashov, L.V. Skripnikov, A.V. Titov, A.N. Petrov The 3 spin \textonehalf particles in $^{\mathrm{207}}$PbF (both nuclei and the unpaired electron) combine to produce the neardegeneracy of two levels of opposite parity, as verified by Fourier transform microwave (FTMW) spectroscopy [1]. This makes it an ideal candidate for the study of chargeparity violation effects and the variation of fundamental constants [2]. Further theoretical work has improved our detailed understanding of both $^{\mathrm{207}}$PbF and $^{\mathrm{208}}$PbF [3], and the theoretical indication that the finely split $+$/ parity levels grow monotonically closer for higher vibrational states has held up as we have extended our experimental results up to v $=$ 6 and v $=$ 7, respectively. We will also present PbF vibrational lifetime calculations along with a new global fit for existing BaF microwave data. TJS acknowledges support from Contract No. DESC0012704 with the U.S. Department of Energy, Office of Science, supported by its Division of Chemical Sciences, Geosciences and Biosciences within the Office of Basic Energy Sciences., as do RM, AB, YK, {\&} JML from Pomona College {\&} JUG from the Deutsche Forschungsgemeinschaft (DFG). $^{\mathrm{1}}$ R. Mawhorter,\textit{ et al}., Phys. Rev. A \textbf{84}, 022508 (2011). $^{\mathrm{2}}$ V.V. Flambaum, \textit{et al.}, Phys. Rev. A \textbf{88}, 052124 (2013). $^{\mathrm{3}}$ L.V. Skripnikov, \textit{et al}., Phys. Rev. A \textbf{90}, 064501 (2014). [Preview Abstract] 

E01.00082: Longlived complexes and the role of chaos in ultracold molecular collisions N. Balakrishnan, J. F. E. Croft, B. K. Kendrick Thermally averaged lifetimes for complexes formed during ultracold elastic collisions of K$_2$ with Rb, from numericallyexact quantumscattering calculations, are shown to be in remarkable agreement with the predictions of simple densityofstates models. The validity of such models is of current interest as they suggest the cause of trap loss in ultracold gases of alkalidimers is longlived complexes. Longlived complexes correspond to narrow scattering resonances which we examine for the statistical signatures of quantum chaos, finding that the positions and widths of the resonances are in good agreement with the WignerDyson and PorterThomas distributions respectively. [Preview Abstract] 

E01.00083: Ultracold Gas of Fermionic Molecules in the Triplet Ground State Juliana Park, Timur Rvachov, Hyungmok Son, Martin Zwierlein, Alan Jamison, Wolfgang Ketterle The ability to produce and manipulate ultracold gases of molecules in welldefined internal states offers opportunities to study quantum chemistry, manybody physics, and quantum information processing. The NaLi molecule, the lightest bialkali molecule, in the triplet ground state is notable for its nonzero electric and magnetic dipole moments and long collisional lifetime due to its predicted small universal loss rate. This enables us to investigate the complexity of chemical reactions by finding links to scattering theory. Also, we can seek the possibility of quantum simulation in manybody physics aided by longrange interactions between the molecules. We have previously made the longlived triplet ground state molecules through stimulated rapid adiabatic passage from Feshbach molecules and discovered the hyperfine structure. We report results of recent collisional studies with our triplet state molecules. [Preview Abstract] 

E01.00084: Stabilizing the Magnetic Field using a ProportionalIntegralDerivative Feedback Circuit for Square Helmholtz Coils in a LaserCooled Atoms Experiment Caitlyn Ward, Jonathan Wrubel Achieving magnetic field stability below the 1 mG level typically requires an active feedback system. We present our system for actively stabilizing the magnetic field in our lasercooled atom experiment. Our system measures the magnetic field from DC to 1 kHz with a lownoise fluxgate magnetometer and provides feedback to a pair of square Helmholtz coils using an analog ProportionalIntegralDerivative feedback circuit. [Preview Abstract] 

E01.00085: An apparatus for a SteadyState Atom Laser Shayne Bennetts, ChunChia Chen, Rodrigo González Escudero, Benjamin Pasquiou, Florian Schreck Strontium represents an ideal platform for developing a steadystate atom laser with potential applications in areas from interferometry to superradiant clock lasers. Traditional quantum gas machines have been limited to pulsed operation by the incompatibility of evaporation and laser cooling, which are routinely required to reach degeneracy. We will present details of the apparatus we have developed for producing a steadystate Bose Einstein condensate and our approach to construct a steadystate atom laser. Our machine tackles this goal by simultaneously cooling atoms in spatially separated regions on both the broad 30MHz and narrow 7.4kHz linewidth Sr transitions [1]. In this way we are able to continuously load a dipole trap at high phase space density in which a Stark shift protected [2] dimple trap collects and concentrates the coldest atoms. We describe recent progress in which we have produced steadystate atomic clouds with phasespace densities above unity and our ongoing efforts to produce a steady stateBEC and atom laser. [1] S. Bennetts et al., Phys. Rev. Lett. 119, 223202(2017). [2] S. Stellmer et al., Phys. Rev. Lett. 110, 263003(2013). [Preview Abstract] 

E01.00086: Vortex structure in p+ip superfluid mixture with Bose JingBo Wang, JianSong Pan, Yi Wei We study the vortex structure of p+ipwave interaction fermion superfluid with Boson, including the majorana zero mode stay in the center of vortex, due to charity symmetry of 2D p+ip wave superfluid. we find with the Bose in the core of fermi vortex, it will efficiently influence the vortex structure, and the Bose will by trapped in the center of the core. more over, if the Bose has one angular momentum, it will shaped the core to a double minimum and gives the current a double peak structure. above all the zero mode always hold in the topological regime, but the wave function will shift from the gauss form to ring type with the interaction between Bose fermi increase. [Preview Abstract] 

E01.00087: Detecting atomic rotation via cavity optomechanics Mishkat Bhattacharya, Kristian Feliz We theoretically explore detection of atomic rotation using cavity optomechanics. We consider the characterization of single atom rotation using optical beams carrying orbital angular momentum (OAM). The single atom system is relevant to quantum information protocols that rely on OAM, including but not limited to quantum memories. We also investigate the cavity optomechanical sensing of rotation of atomic BoseEinstein condensates, particularly persistent currents in ring traps. These systems are of importance to atomtronic applications, and the role of angular momentum in the system is of interest with regard to phenomena such as phase slips. [Preview Abstract] 

E01.00088: AlkaliMetal Mixture for Synthetic Alkali Vapor Density Reduction Justin Brown, Colin Hessel, Joel Hensley Physical Sciences Inc. (PSI) has demonstrated a method to synthetically reduce the equilibrium saturated vapor density of alkali atoms through the use of an alkalimetal mixture. The reduction is based on the physical principle of Raoult's Law where the vapor density of components in a mixture is reduced by the mole fraction represented in the mixture and can be continuously adjusted with the mixing ratio. PSI has produced a series of alkalimetal mixtures demonstrating controllable reduction of the rubidium vapor density by up to 10,000 at equilibrium. Binary and ternary rubidium mixtures with sodium and lithium have produced rubidium densities of $\sim$10$^8$/cm$^3$ with total vacuum pressures of $10^{7}10^{8}$ Torr at 85$^\circ$C to provide vacuum conditions compatible with operation of a magnetooptical trap (MOT) at 85$^\circ$C. The alkali mixture provides a new passive atom source for portable atombased sensors operating outside the laboratory where lowest power thermal regulation over the 0$^\circ$C85$^\circ$C commercial temperature range occurs at elevated temperatures using only a heater. [Preview Abstract] 

E01.00089: New method to determine nuclear charge radius based on EUV spectroscopy of Nalike ions R. Silwal, A. Lapierre, J. D. Gillaspy, J. M. Dreiling, S. A. Blundell, D. FNU, A. Borovik. Jr, G. Gwinner, A. C.C. Villari, Y. Ralchenko, E. Takacs Nuclear charge radii are a fundamental property that is key to understanding nuclear structure. Their measurement with electron scattering and muon spectroscopy is accurate but limited to stable isotopes. Though relative shifts in charge radii along isotope chains from optical isotope shifts measurements are very precise, manyelectron atomic calculations can contribute to systematic offsets. Transition energies of Nalike ions are particularly sensitive to nuclear size and their simple electronic structure results in highly accurate atomicstructure calculations. A new method based on EUV spectroscopy of Nalike ions observed in an electron beam ion trap has been implemented to measure the isotope shift of Nalike D1 (3s  3p$_{\mathrm{1/2}})$ transitions between $^{\mathrm{124}}$Xe and $^{\mathrm{136}}$Xe. Comparison of the measured shift with atomicstructure calculations was used to determine the meansquare charge radius difference to be 0.297(28) fm$^{\mathrm{2}}$, which agrees with previous measurements. The new method requires much smaller sample size than conventional methods, making it ideal to take first measurements of shortlived radioactive isotopes when new isotope beam facilities come online in near future. [Preview Abstract] 

E01.00090: Proposed Measurement of tensor polarizability of ground state Cesium atoms Teng Zhang, David Weiss We propose a new way to measure the tensor polarizability of Cesium ground states. The measurement will take advantage of the apparatus we are using to search for the electron electric dipole moment (eEDM), with cold atoms trapped in optical lattices and in high electric fields. By independently measuring the population in each individual magnetic sublevel, we will simultaneously measure transitions between the m$_{\mathrm{F}}=$\textpm 2 states and the m$_{\mathrm{F}}=$\textpm 3 states. With this direct measurement of tensor energy shifts, we anticipate an order of magnitude improvement in precision over the current experimental value [S. Ulzega, et al,~Phys. Rev. A~75, 042505 (2007)1], ultimately limited by our ability to account for tensor light shifts due to the optical lattice. [Preview Abstract] 

E01.00091: An in vacuo optical polarimeter K.W. Trantham, T.J. Gay Polarimetric analysis of light is an invaluable tool in understanding processes such as atomic collisions. In such experiments, the interaction of interest is typically in vacuum, whereas the optical polarimeter is situated in the lab, at atmosphere. This arrangement therefore requires a vacuum window. Stress on the window can alter the polarization of the transmitted light. For precise measurements, understanding and controlling this instrumental error is important. A novel, in vacuo optical polarimeter is discussed. By operating the device in vacuum, the need for a vacuum window is eliminated. The design is demonstrated by measuring the Stokes parameters of light from a strongly, linearlypolarized neon lamp. The source is located in its own independent vacuum system, with a collection lens serving as a vacuum barrier between source and polarimeter. While maintaining the polarimeter under vacuum, we present results showing induced circular polarization correlated to lightsource pressure, suggesting stress induced birefringence of the lens. Data shows that stressing the lens can change the observed, total polarization by as much as 0.7{\%} of the polarization value itself. [Preview Abstract] 

E01.00092: Progress Towards Measurement of the Nuclear Anapole Moment of $^{\mathrm{137}}$Ba Using BaF Molecules Sidney Cahn, Emine Altuntas, Jeffrey Ammon, JaiMin Choi, David DeMille Weak interactions inside the nucleus produce a toroidal current distribution around the axis of nuclear spin. This current distribution, known as the nuclear anapole moment, is the dominant source of nuclear spindependent parity violation (NSDPV) effects for nuclei with mass number A$\ge $20$. $We discuss ongoing work to measure the anapole moment of the $^{\mathrm{137}}$Ba nucleus, by measuring parityviolating state mixing in the molecule BaF. Our experiment amplifies the NSDPV effect by Zeemanshifting rotational/hyperfine levels of opposite parity to near degeneracy. We recently demonstrated unprecedented sensitivity to NSDPV effects, using the abundant isotopologue $^{\mathrm{138}}$Ba$^{\mathrm{19}}$F. Here, the NSDPV effect (due only to the $^{\mathrm{19}}$F nucleus) is known to be negligibly small, so that systematic errors could be definitively evaluated. Here, we describe this demonstration measurement, including an extensive study of systematic errors that should be essentially the same in $^{\mathrm{137}}$BaF. We also discuss \quad planned improvements to our apparatus needed to make an NSDPV measurement using $^{\mathrm{137}}$BaF. [Preview Abstract] 

E01.00093: Probing ferromagnetism with fewfermion correlated spinflip dynamics Georgios Koutentakis, Simeon Mistakidis, Peter Schmelcher According to the Stoner instability, the ferromagnetic phase of a spin1/2 Fermi system occurs for strong interparticle repulsion, resulting in the occupation of states with antioriented spins being energetically forbidden. However, the clean realization of a ferromagnetic phase in quantum gases verifying this viewpoint is elusive. We unravel the stability of a fully polarized onedimensional ultracold fewfermion spin1/2 gas subjected to inhomogeneous driving of the itinerant spins. The existence of a ferromagnetically ordered regime for interaction strengths comparable to the confinement energy is revealed. Within the latter regime, the twobody spinspin correlator unveils that the itinerant spins remain close to be maximally aligned throughout the dynamics, despite the magnitude of the polarization fluctuating between zero and unity. This implies that the interaction alone is not able to stabilize the spin polarization and hence the magnetization of a trapped Fermi gas. [Preview Abstract] 

E01.00094: Bridging the thermoelectric and superfluid fountain effects with ultracold fermions Martin Lebrat, Dominik Husmann, Samuel H\"{a}usler, Philipp Fabritius, Laura Corman, JeanPhilippe Brantut, Tilman Esslinger An outofequilibrium system with temperature and chemical potential gradients needs both heat and matter currents to relax to thermodynamical equilibrium. The relaxation dynamics illuminates the microscopic mechanisms responsible for transport and energy conversion between heat and work, which is of great technological importance for cooling (Peltier effect) or power generation (Seebeck effect). Using two reservoirs of fermionic lithium6 atoms connected by an opticallyshaped constriction, we demonstrate such thermoelectric effects and investigate the influence of interactions and constriction properties. With weak interactions and a 2D constriction, thermoelectric coupling can be optimized by controlling the geometry or introducing disorder. With strongly interacting fermions close to the superfluid transition and a quasi1D constriction, the system evolves towards a nonequilibrium steady state, associated with a reduced heat diffusion and a strong violation of the WiedemannFranz law. Measuring thermoelectric transport coefficients as a function of constriction anisotropy and degeneracy, we underline the analogies and differences between our observations and the celebrated fountain effect shown with superfluid helium4. [Preview Abstract] 

E01.00095: Metastable polar state of a spin1 antiferromagnetic BoseEinstein condensate under a magnetic field gradient Joon Hyun Kim, Seji Kang, Deokhwa Hong, Yongil Shin We study metastable polar states in a spin1 antiferromagnetic spinor BoseEinstein condensate (BEC) under a magnetic field gradient. For negative quadratic Zeeman energy $q$, the system's ground state is an easyplane polar (EPP) state and the sample in an easyaxis polar (EAP) state would undergo a quench evolution into the ground EPP state via spinexchange collision. In the presence of magnetic field gradient, however, we have observed that the BEC prepared in the EAP state becomes dynamically stable down to a certain negative $q$ value. We measure the threshold $q$ value for the metastable EAP state as a function of the field gradient and we also find that the metastable state becomes more robust with decreasing the spatial size of the sample. We will discuss the physical origin of the metastability of the spinor BEC system. [Preview Abstract] 

E01.00096: Entangled state preparation enhanced by reinforcement learning JunJie Chen, You Li Fast and accurate generation of useful quantum states is fundamental to quantum information and quantum precision measurement physics. In actual applications, welldesigned experimental protocols are called for. The recently developed learning frame of reinforcement learning (RL) can maximize a given reward by automatically exploring and exploiting without the necessity of any prior knowledge. This work reports our discovery of an efficient, effective, and high fidelity protocol with RL, that is capable of producing a target TwinFock state by driving external field from an initial polar state of a ferromagnetic spin1 atomic BoseEinstein condensate. For a small system of two atoms, we show that protocol from RL corresponds to the optimized one reaching the quantum speed limit. When illustrated in phase space, it clearly shows that the protocol from RL corresponds almost to a geodesic path connecting the initial and the target state. When applied to a many body system, we find that RL generally can offer a better solution than the old wisdoms such as adiabatic passage {\it etc.} can provide for. Furthermore, we find the RL protocol is robust to various types of noises in real experiments. [Preview Abstract] 

E01.00097: Cavitymediated tunable spin mixing in spinor atomic BoseEinstein condensates Ming Xue, JunJie Chen, ZhiFang Xu, Li You Spin mixing usually refers to the dynamics originating from binary spin exchange collisions in a spinor atomic BoseEinstein condensate. This work presents a practical scheme for realizing spin mixing with tunable interaction strength and effective quadratic Zeeman shift by placing the condensate in an optical cavity, whereby two atomic Raman transitions are accomplished via a cavity photon and two laser beams, leading to the generation of an effective spinexchange interaction. The effective Hamiltonian are derived by using FloquetMagnus expansion. For increased strength, the frequencies of the two $\sigma$polarized lasers are chosen to compensate the spinexchange energy mismatching. With atoms far offresonant due to a large bias magnetic field and the cavity photonic mode only virtually excited, our scheme is found to be robust against cavity dissipation and magnetic field noise. [Preview Abstract] 

E01.00098: Spinincoherent Luttinger liquid of onedimensional SU($\kappa$) fermions HsiangHua Jen, Sungkit Yip We investigate spinincoherent onedimensional (1D) SU($\kappa$) fermions in a harmonic trap. Specifically we focus on TonksGirardeau gas limit where its density is sufficiently low that effective repulsions between atoms become infinite. In such case, spin exchange energy of 1D SU($\kappa$) fermions vanishes and all spin configurations are degenerate, which automatically puts them into spinincoherent regime. In this limit, we can write down the spatial wave functions by the conventional Slater determinant, and furthermore we are able to express the singleparticle density matrices in terms of those of anyons. This allows us to numerically simulate the number of particles up to $N=32$. We numerically calculate singleparticle density matrices for (1) equal populations for each components (balanced) and (2) all Sz manifolds included. We find their momentum distributions are broadened due to highly degenerate spin configurations, a signature of spinincoherent regime. We then compare numerically calculated high momentum tails of momentum distributions with analytical predictions which are proportional to $1/p^{4}$, in good agreement. Thus, our theoretical study provides a direct comparison with experiments of repulsive multicomponent alkaline earth fermions. [Preview Abstract] 

E01.00099: SpinInteraction Effects for Ultralongrange Rydberg Molecules in a Magnetic Field Christian Fey, Frederic Hummel, Peter Schmelcher Ultralongrange Rydberg molecules (ULRM) are ``giant molecules'' consisting of a Rydberg atom and one or more polarizable ground state atoms [1,2]. The BornOppenheimer potential surfaces of these molecules mimic the oscillatory structure of the Rydberg wave function and are therefore extremely sensitive to weak external fields. This property can be exploited to control the molecular geometry, e.g. to orient the molecular axis relative to a given magnetic field axis [3,4]. On our poster we will focus on the role of different spin couplings for the formation of Rb $d$state ULRM in magnetic fields, e.g. the relative configuration of the Rydberg spin and the electronic spins of the ground state atoms (singlet vs. triplet) or the hyperfine configurations. We'll see that the magnetic field offers possibilities to create a large variety of molecular states in different spin configurations as well as in different spatial arrangements [5]. [1] Greene, Dickinson, Sadeghpour, PRL 85, 2458 (2000). [2] Bendkowsky, Butscher, Nipper, Shaffer, L\"ow, Pfau, Nature 458, 1005 (2009). [3] Kurz, Schmelcher, J. Phys. B 47 165101 (2014). [4] Krupp, Gaj, Balewski, Ilzh\"ofer, Hofferberth, L\"ow, Pfau, Kurz, Schmelcher, PRL 112, 143008 (2014). [5] Hummel, Fey, Schmelcher, arxiv 1711.08748 [Preview Abstract] 

E01.00100: Dual Species Rydberg and Collisional Interactions in an Optical Dipole Trap Matthew Ebert, Garrett Hickman, Alphonse Marra, Xiaoyu Jiang, Trent Graham, Mark Saffman We present progress in demonstrating Rydberg interactions between a single Rb and a single Cs atom simultaneously trapped in a single 976 nm optical tweezer. Rydberg levels in heteronuclear systems have different quantum defects, as opposed to homonuclear systems, and can therefore be chosen to minimize the Forster defect and increase the Rydberg interaction strength beyond symmetric Rydberg pairs at comparable energy levels. Additionally, multispecies systems are distinguishable and can be frequency multiplexed in a straightforward manner. Frequency multiplexing both the state preparation and state readout is used in characterizing elastic and inelastic collision rates between Rb and Cs, as well as enabling crosstalk free ancilla measurements for quantum error correction. [Preview Abstract] 

E01.00101: Using phase space methods to study manybody localization in spin systems with longrange interactions Sean Muleady, Arghavan SafaviNaini, Michael L. Wall, Rahul Nandkishore, Ana Maria Rey Manybody localized (MBL) systems fail to thermalize and may be used as robust quantum memories with intriguing entanglement properties. In onedimensional systems with shortrange interactions, we have been able to gain an excellent understanding of the nature of the MBL phase. However, very little is known about the fate of the MBL phase when the interactions are extended to long range. Here, we use extensive numerical simulations to study the existence and characteristics of an MBL phase in the presence of powerlaw decaying interactions. We use matrix product state (MPS) methods, which are exact but limited to modest system sizes, as well as approximate phase space techniques based on the discrete truncated Wigner approximation (DTWA), which allow the exploration of larger systems sizes, longer times, and even higher dimensions. Additionally, we characterize the dynamical behavior of relevant observables, such as entanglement entropy, quantum Fisher information, and imbalance, and assess their utility in identifying the MBL phase in experiments. [Preview Abstract] 

E01.00102: Progress towards a dual species quantum repeater node with a highfinesse fiber resonator Garrett Hickman, Matthew Ebert, Trent Graham, Xiaoyu Jiang, Sudheer Vanga, Randall Goldsmith, Mark Saffman We report on progress towards a high finesse fiber resonator to be used in the construction of a dual species quantum repeater node. A highfinesse cavity will be used to allow the state of a single incoming photon to be efficiently mapped onto the collective atomic state of an ensemble of Rb atoms. Entanglement swapping between the Rb ensemble and a qubit defined by the ground state hyperfine manifold of a Cs atom simultaneously trapped within the cavity can then be performed using Rydberg interactions. We describe our work on a preliminary implementation of this system, in which an ensemble of cold Rb atoms is trapped within a highfinesse fiber cavity. This system will allow for the study of Rydberg excitation of Rb atoms in the vicinity of stray electric fields due to surface charges on the fiber tips. [Preview Abstract] 

E01.00103: Relative magnitude of ``good'' and ``bad'' collisions Bo Gao We give a more complete presentation of the quantum Langevin (QL) model for neutralneutral bimolecular interactions and reactions [Gao, Phys. Rev. Lett. \textbf{105}, 263203 (2010)], and use it to provide a general discussion of the relative magnitude of ``good'' (elastic) and ``bad'' (inelastic or reactive) collisions. We show that this relative magnitude is determined by the longrange potential, and has the general characteristics of being ``bad'' at low temperatures and ``good'' at high temperatures. [Preview Abstract] 

E01.00104: Collisional studies of ultracold $^{23}$Na$^{87}$Rb molecules Xin Ye, Mingyang Guo, Junyu He, Maykel GonzalezMartinez, Romain Vexiau, Goulven Quemener, Dajun Wang We report a series of experiments on collisions of ultracold bosonic $^{23}$Na$^{87}$Rb molecules in their quantum ground states. First, we studied the collisions of molecular samples with distinct chemical reactivities by making use of the vibrational excitation. We observed very similar loss and heating, regardless of the chemical reactivities. Second, we studied the dipolar collision with induced dipole moments as large as 0.7 Debye. We observed a stepwise enhancement of losses as manifestations of couplings between different partial waves induced by the increasingly stronger dipolar interactions. Our experimental data show nice agreements with the model based on twomolecule complex formation. [Preview Abstract] 

E01.00105: Ultracold collisions of spinpolarized SrF$(^2\Sigma^+)$ molecules with Rb($^2\mathrm{S}$) atoms in an external magnetic field Masato Morita, Maciej B. Kosicki, Piotr S. \.Zuchowski, Timur V. Tscherbul Recent advances in molecular laser cooling have enabled the production of cold, trapped SrF$(^2\Sigma^+)$ and CaF$(^2\Sigma^+)$ radicals at submilliKelvin temperatures. To explore the feasibility of sympathetic cooling of SrF radicals using ultracold Rb atoms in a magnetic trap, we carry out accurate ab initio and quantum scattering calculations of ultracold RbSrF collisions. In spite of the significant anisotropy in the interaction potential between Rb and SrF, we find that fully converged scattering calculations on RbSrF collisions are possible using a total angular momentum basis including up to 125 rotational states of SrF and up to 3 total angular momentum blocks. We examine the sensitivity of the scattering cross sections to small variations of the interaction potential and use a statistical approach to estimate the success probability of atommolecule sympathetic cooling. [Preview Abstract] 

E01.00106: ABSTRACT WITHDRAWN This abstract has been withdrawn. [Preview Abstract] 

E01.00107: A high density source of cold, slow and rotationally pure polar molecules Thomas Gantner, Xing Wu, Manuel Koller, Martin Zeppenfeld, Sotir Chervenkov, Gerhard Rempe Cold polar molecules provide fascinating research possibilities in physics and chemistry. However, densities of cold and slow molecules achieved in past experiments have been unsatisfactory for many applications. The combination of cryogenic buffer gas cooling with our centrifuge decelerator solves this problem. We achieve a record high flux exceeding $10^{10}s^{1}$ and densities up to $10^{9}cm^{3}$ of internally cold polar molecules with a single state purity of up to $92\%$ $\footnote{X. Wu et al., \textbf{ChemPhysChem} 17, 3631, (2016)}$ at kinetic energies corresponding to less than 1K $\footnote{X. Wu et al., \textbf{Science} 358, 645, (2017)}$. As the method only relies on the dipole moment, it is applicable to a wide range of even complex, polyatomic molecular species ($ND_3$, $CH_3F$, $CF_3CCH$, etc.). Besides enabling detailed collision studies our technique could serve as an ideal source for trapping and cooling experiments. [Preview Abstract] 

E01.00108: Lifetime measurement of nD$_{\mathrm{3/2}}$ and nD$_{\mathrm{5/2}}$ Rb Rydberg states. Barbara F. Magnani, Cristian A. Mojica Casique, Luis G. Marcassa Accurate measurements of the lifetime of Rydberg states can provide powerful tests for theoretical calculations of dipole matrix elements, oscillator strengths, core polarizabilities, and influence of blackbody radiation on radiative lifetimes. Alkali atoms have been used both theoretically and experimentally as prototypes for the study of these problems. The most accurate values for Rb Rydberg lifetimes to date have been measured in a magneto optical trap at a roomtemperature environment [1]. In this work, we have measured the lifetime of nD$_{\mathrm{3/2}}$ and nD$_{\mathrm{5/2}}$ states of Rb as a function of principal quantum number using a cw 480 nm laser for Rydberg excitation. We have used a 1064 nm laser to measure the photoionization rate as well. We will present the description of the experimental setup, followed by the results and the discussion, in which we present a comparison of our measurement with existing theory [2]. [1] L. G. Marcassa, Phys. Scr. T134, 014011 (2009) [2] I. I. Beterov, I. I. Ryabtsev, D. B. Tretyakov, and V. M. Entin, Phys. Rev. A 79, 052504 (2009). [Preview Abstract] 

E01.00109: Progress towards an apparatus capable of studying strong optical nonlinearities using Rydberg Electromagnetically Induced Transparency Josiah Sinclair, Kent FisherBosma, Aephraim Steinberg The strong dipoledipole interaction between Rydberg atoms provides an exciting platform for quantum nonlinear optics. We report on progress towards studying various nonlinear effects at the singlephoton level using Rydberg electromagnetically induced transparency (EIT). Our apparatus consists of a Rubidium magnetooptical trap (MOT), a ``probe'' beam at 780nm locked on resonance that can be modulated on and off quickly and scanned in frequency synchronously with the atom cycle, and a ``coupling'' beam at 480nm that is locked to a Rydberg transition using EIT spectroscopy and can be modulated asynchronously. The beams are overlapped and counterpropagated through the MOT cloud, and the transmission of the probe is recorded using an avalanche photodiode. We observe EIT at low n (n$=$50), where the interaction length scales are small compared to the atom cloud size and beam focus. With the addition of a crossed optical dipole trap to match the atom cloud size to the same length scale as the interactions, we will be able to study photonphoton interactions via Rydberg EIT. An intermediate goal is to study weak nonlinearities in a nonblockaded regime for number state squeezing as an exploratory step toward a quantumnondemolition measurement of photon number. [Preview Abstract] 

E01.00110: Study of the electron temperature in an ultracold Rydberg plasma Duncan Tate, Gabriel Forest, Yin Li, Edwin Ward, Anne Goodsell We report a systematic experimental and numerical study of the electron temperature in ultracold Rydberg plasmas. Specifically, we have measured the asymptotic expansion velocities of ultracold neutral plasmas (UNPs) which evolve from cold, dense samples of Rydberg rubidium atoms using ion timeofflight spectroscopy. We have also simulated numerically the interaction of UNPs with a large reservoir of Rydberg atoms to obtain data to compare with our experimental results. We find that for Rydberg atom densities in the range $10^7  10^9$ cm$^{3}$, for $n > 40$, the initial electron temperature in the Rydberg plasma is insensitive of the ionization mechanism which seeds the plasma. Instead, it is determined principally by the plasma environment when the UNP decouples from the Rydberg atoms at the end of the avalanche regime. On the other hand, plasmas from Rydberg samples with $n \le 40$ evolve with no significant additional ionization of the the remaining atoms once a threshold number of ions has been established. The dominant interaction between the plasma electrons and the Rydberg atoms is one in which the atoms are deexcited, a process that competes with adiabatic cooling so that the UNPs have a low Coulomb coupling parameter for electrons, $\Gamma_e \sim 0.01$. [Preview Abstract] 

E01.00111: A pressuretuned FabryPerot interferometer for laser stabilization and tuning Keegan Orr, Ian George, Andrew Lesak, Molly Eder, Aaron Reinhard Experiments involving a weak atomic transition, such as a transition to Rydberg states, require a stable reference to lock the excitation laser, as well as a method to precisely tune the laser. A stable, tunable reference has been implemented through the use of a pressuretuned FabryPerot interferometer [1]. A fixedlength interferometer cavity is housed inside a sealed enclosure, and the resonance condition of the interferometer is tuned by changing the pressure of the gas inside. This, in turn, changes the index of refraction of the gas. We present a new design for a pressuretuned FabryPerot interferometer which is characterized by a tuning range of several GHz, as well as improved temperature stability, tuning precision, and tuning repeatability [1]. Our interferometer is made almost exclusively of low cost, offtheshelf parts and utilizes air inside the enclosure, rather than a high molecular weight gas. We will present measurements quantifying the performance of our interferometer, including its temperature stability and tunability. $^{\mathrm{1}}$Hansis, \textit{et al}, Rev. of Scientific Instruments, \textbf{76}, 033105 (2005) [Preview Abstract] 

E01.00112: Efimov states embedded in a quenched unitary Bosecondensed gas. Victor Colussi, Silvia Musolino, Servaas Kokkelmans Three identical bosons at unitarity may form a series of threebody bound states whose spectrum was first given by Efimov [1]. Recently, a macroscopic population of Efimov molecules was measured for the first time in a Bosecondensed gas quenched to unitarity [2]. Through the method of cumulants [3,4], we study threebody physics in the manybody context. We report preliminary results for the spectrum of two and threebody bound states embedded in the quenched unitary Bosecondensed gas. This study is in preparation for studying the dependence of macroscopic observables on Efimov physics. [1] V. Efimov, Sov. J. Nucl. Phys.,\textbf{ 29}, 546 (1979). [2] C. E. Klauss, X. Xie, C. LopezAbadia, J. P. D'Incao, Z. Hadzibabic, D. S. Jin, E. A. Cornell, Phys. Rev. Lett.\textbf{ 119} (14), 143401 (2017). [3] T. K\"{o}hler and K. Burnett, Phys. Rev. A~\textbf{65}, 033601 (2002). [4] M. Kira, Nat. Comm., 6:6624, (2015). [Preview Abstract] 

E01.00113: Precise Characterization of Fewbody Interactions in \textsuperscript{39}K Xin Xie, Roman Chapurin, Michael Van de Graaff, Carlos LopezAbadia, Jared Popowski, Jun Ye, Eric Cornell Dilute ultracold quantum gases provide an ideal platform to study shortrange interactions in a controlled way. Bosonic species present rich physics owing to the twobody and threebody interactions. We will report some of the first results taken with our new \textsuperscript{39}K machine. By doing radio frequency (r.f.) dissociation, we are able to measure the binding energy of Feshbach molecules within an uncertainty of subkilohertz. This spectroscopic method not only enables us to locate the pole of the Feshbach resonance with great precision but also assists the detection of small energy shift due to fewbody interactions. [Preview Abstract] 

E01.00114: A New Lithium (Li)Cesium (Cs) Machine for The Study of Quasiparticle Localization in BoseEinstein Condensates. YiDong Chen, WeiXuan Li, ChiaShan Li, AiLin Chen, MinEn Chou, ChunHsien Kuo, ChenYu Jhang, ShihKuang Tung Mixtures of quantum gases provide opportunities to explore new phenomenon and to verify theories that are beyond the extent of single component systems. Here we propose a new LiCs machine to study the fascinating physics lying behind the mixtures. The machine is designed to create both BoseBose~$^{\mathrm{133}}$Cs$^{\mathrm{7}}$Li and BoseFermi~$^{\mathrm{133}}$Cs$^{\mathrm{6}}$Li $^{\mathrm{\thinspace }}$ mixtures. Exploiting the huge disparity in Li and Cs, we plan to study quasiparticle localization in BoseEinstein condensates, one species acting as disorder for quasiparticles of the second species, and also use the machine to study systems composed of two kinds of superfluid with large mass disparity and different statistics. [Preview Abstract] 

E01.00115: Experimental demonstration of high fidelity ${}^{133}$Ba$^+$ hyperfine qubits David Hucul, Justin Christensen, Eric Hudson, Wesley Campbell Wellisolated trapped atomic ions are attractive candidate qubits because of their spectroscopic features. Ions with nuclear spin $I =1/2$ allow fast, highfidelity initialization of hyperfine clock qubits with coherence times exceeding 10 minutes. Longlived Dstates allow for electron shelving of a qubit state to achieve ultralow readout errors of the qubit. Visible wavelength transitions for laser cooling and qubit manipulation allow the leveraging of existing photonics technology. ${}^{133}$Ba$^+$ is the only atomic ion to simultaneously possess all of these features. The successful trapping and laser cooling of ${}^{133}$Ba$^+$ along with the characterization of its excited state spectroscopy (1) has allowed for the first hyperfine qubit manipulations of this goldilocks atomic ion. We implement electron shelving to dramatically increase the readout fidelity of the hyperfine qubit without the need for efficient light collection. Our measurements of the spectroscopic structure of ${}^{133}$Ba$^+$ suggest this qubit could have broad applications in quantum information processing, quantum networking, and the construction of compact quantum sensors and clocks.\\ (1). D. Hucul, J.E. Christensen, E.R. Hudson, W.C. Campbell, PRL 119, 100501 (2017). [Preview Abstract] 

E01.00116: Optically generated vortexantivortex superpositions in twocomponent BoseEinstein condensate Anal Bhowmik, Pradip Kumar Mondal, Sonjoy Majumder, Bimalendu Deb Allen and coworkers first brought up the realization that vortex beam can carry well defined orbital angular momentum (OAM) associated with its helical phase front. Apart from OAM, light has Spin angular momentum (SAM) associated with its polarization. Transfer mechanism of OAM and SAM from optical vortex to atoms and molecules is well known. Here, we investigate the microscopic interaction of a Laguerre Gaussian (LG) beam with a trapped twocomponent BoseEinstein condensate (BEC). We consider $^{87}$Rb BEC in two hyperfine spin components and the wavelength of LG beam is comparable to the atomic deBroglie wavelength. Competitions between intra and intercomponent interactions produce interesting structure in the ground state of BEC which is applied to calculate the Rabi frequency of two photon stimulated Raman transition. Our analysis shows that the profile of the Rabi frequencies over the intercoupling strengths can infer the properties of the BEC components. We demonstrate coherence in vortexantivortex in terms of intercomponent interactions when both the components are subjected to appropriate Raman transitions. [Preview Abstract] 

E01.00117: A Platform for QuantumStateResolved Hydrocarbon Chemistry Gary Chen, Tiangang Yang, Arthur Suits, Wesley Campbell, Eric Hudson We are working towards a new platform for quantumstateresolved ionmolecule chemistry by utilizing a combination of cryogenic buffer gas cooling, lasercooled ion sympathetic cooling, and integrated mass spectrometry in an RF Paul trap. Cold molecular species produced in a cryogenic buffer gas beam react with trapped atomic carbon ions. Since charged reaction products are also trapped, ion imaging and time of flight mass spectrometry are used to study the reaction rates and identify the products. We report results on the characterization of a cold water beam reacting with trapped, cooled ions. Product branching and rates between neutral water molecules and beryllium/carbon ions are observed. [Preview Abstract] 

E01.00118: Equilibrium and Dynamics of a BoseFermi Quantum Mixture with Strong Mass Imbalance Krutik Patel, Brian DeSalvo, Geyue Cai, Cheng Chin We present our work with quantum degenerate mixtures of bosonic $^{133}$Cs and fermionic $^{6}$Li. Due to the strong mass imbalance and differing quantum statistics, the BoseEinstein condensate (BEC) is fully immersed in the much larger degenerate Fermi gas. By tuning the magnetic field near an interspecies Feshbach resonance, we control the interactions between the BEC and surrounding fermions. This allows the study of equilibrium phases and dynamics of BoseFermi mixtures as a function of scattering length. In equilibrium, mean field theory predicts BoseFermi mixtures exhibit three distinct phases. With weak interactions, the components are miscible. With strong attractive interactions there should be a collapse, and with strong repulsive interactions the components should phase separate. However, this picture has proved overly simplistic. We observe no such collapse in our system and find a regime where fermions are fully confined by the BEC. To study dynamics, we measure frequency shifts and damping rates of the bosonic dipole oscillations as a function of interspecies interaction strength. For weak interactions, we observe shifts of the frequency and damping rates consistent with the meanfield calculation. For strong interactions the data disagree with this model. [Preview Abstract] 

E01.00119: Emergence of novel dynamical phases in a nonMarkovian open quantum system Yogesh S Patil, Hil Fung Harry Cheung, Mukund Vengalattore We experimentally realize a driven dissipative continuous phase transition in a parametrically driven twomode system with nonMarkovian systembath interactions. We show that due to the influence of these nonMarkovian interactions, the phase diagram is significantly modified and results in~an emergent phase characterized by a dynamic order parameter with a novel broken $U(1)\times \mathbf{{\rm Z}}_{2} $ symmetry. Further, by linearly quenching the system from the disordered phase to the ordered phase, we demonstrate that the initial growth of order has a universal behavior that conforms to a conventional dynamical critical theory. Moreover, we observe a dynamical hysteresis in the system for cyclic quenches across criticality because of the divergent relaxation time and nonadiabatic dynamics near the critical point. While in equilibrium continuous phase transitions the area of this hysteretic cycle scales as a single power law with the quench rate, we observe the scaling exponent here to depend on the quench rate, suggesting that nonMarkovian systembath interactions may lead to timescaledependent critical exponents. Such reservoirengineered systems and dynamical phases can help shed light on the universal aspects of dynamical phase transitions in nonequilibrium systems, and aid in the development of techniques for the robust generation of entanglement and quantum correlations at finite temperatures. \newline [1] H. F. H. Cheung, Y. S. Patil and M. Vengalattore, arXiv: 1707.02622 [Preview Abstract] 

E01.00120: Influence of NonMarkovian systembath interactions on thermodynamic process efficiencies Hil Fung Harry Cheung, Jialun Luo, Yogesh S Patil, Mukund Vengalattore Efficiency and power of Markovian heat engines follow well established limits such as the Carnot limit and the CurzonAhlborn bound. However, the bounds in the presence of nonMarkovian systembath interactions remain elusive. Here, we realize a nonMarkovian heat engine in an optomechanical system, and explore its power and efficiency at various parameter regimes. We also propose extending this heat engine to the quantum regime in a hybrid quantum system that couples a cavity optomechanical device to an ultracold spin ensemble. These experiments are potential platforms for studying generalized quantum thermodynamic bounds for quantum heat engines. [Preview Abstract] 

E01.00121: Towards a Quantum Spin Transducer with Mechanical Resonators Emma Rosenfeld, Jan Gieseler, Arthur Safira, Aaron Kabcenell, Martin Schuetz, Jack Harris, Mikhail Lukin Interfacing spins and mechanical degrees of freedom allows for a variety of applications and experimental observations. For example, one can deterministically entangle pairs of spins through their coherent coupling with the dynamics of a resonator, even for large spinspin distance separations and thermal resonator states. Additionally, the resonator could be cooled close to the quantum ground state by bringing a strongly coupled bath of spins into resonance, introducing the possibility of single phonon experiments and quantum state preparation of a mesoscopic object.~Here, we describe technical progress towards strong, coherent coupling of Nitrogen Vacancy (NV) center spin qubits in diamond, to a mechanical resonator, via a magnetic field gradient. Using the NVs as sensors, we observe the AC motion of a silicon nitride, doubleclamped, beam resonator. We also propose a scheme to use an ensemble of NV defects to cool the resonator close to its quantum ground state, using technically feasible parameters (Q of about one million, resonator frequency of 1 MHz, at a temperature of about 4 K). [Preview Abstract] 

E01.00122: High signal, low background detection of a single trapped neutral atom Margaret E. Shea, James A. Joseph, Paul M. Baker, Jungsang Kim, Daniel J. Gauthier Single neutral atom trapping provides a promising platform for the study of fundamental physics and quantum information protocols. Detecting single neutral atoms is critical for the utility of these traps. Here we report on a high signal, low background detection system for a faroffresonant trap (FORT) containing a single \textsuperscript{87}Rb atom. The system consists of an offtheshelf invacuum lens and singlephotoncounting avalanche photodiode. An EMCCD camera is used for initial alignment and imaging. We use a probe/cool detection scheme that is insensitive to the atomic ground state. Through careful optimization of the scheme frequencies and polarization, we are able to collect $\geq$50,000 counts per second emitted primarily on the $F=2 \rightarrow F'=3$ transition. We achieve signaltobackground ratios in excess of 25. The detection scheme is nondestructive and the atom can survive in the FORT for multiple detections. We show how the results scale with detectbeam frequency, power, polarization, and duration. This scheme sets the stage for high fidelity, nondestructive quantum state detection. [Preview Abstract] 

E01.00123: Filling the gap between quantum nocloning and classical duplication Minghao Wang, Qingyu Cai The correspondence principle suggests that a quantum description for the microworld should be naturally transited to a classical description in the classical limit, while it seems there were a big gap between quantum nocloning and classical duplication. In this paper, we prove that a classical duplication process can be realized with a universal quantum cloning machine. In classical world, information is encoded in a large number of quantum states instead of one quantum state. When errors occurred in a small part of the quantum states were tolerated, the fidelity of duplicated copies of classical information could approach unity. That is, classical information duplication is equal to a redundant quantum cloning process with selfcorrecting. [Preview Abstract] 

E01.00124: Progress towards entangling neutral atom ensemble qubits using Rydberg interactions Minho Kwon, Chris Young, Matt Ebert, Thad Walker, Mark Saffman We report on progress towards higher fidelity preparation and control of ensemble qubits using Rydberg blockade. The scalability and strong coupling to photons of ensemble qubits make them promising building blocks for quantum networks. Our previous demonstration of the preparation of ensemble qubits was limited to moderate fidelity \(<60\%\), possibly due to the presence of atom pairs with small separations leading to Rydberg blockade leakage. In order to suppress unwanted Rydberg interaction channels we add a bluedetuned 1D lattice on top of the existing reddetuned dipole trap, thereby imposing constraints on the minimal atom separations. We study the effect of lattice insertion on the fidelity of ensemble state preparation and Rydbergmediated gates. Cooperative scattering from a 1D atomic array is also studied. An automatic alignment system to improve the pointing stability of the tightly focused Rydberg excitation beams is also presented. [Preview Abstract] 

E01.00125: Quantum ManyBody Physics with Photons Ningyuan Jia, Nathan Schine, Alexandros Georgakopoulos, Albert Ryou, Claire Baum, Logan W. Clark, Ariel Sommer, Jonathan Simon We present our apparatus for synthesizing topological quantum materials using photons in an optical resonator. Photons in a planar cavity undergo transverse oscillations analogous to massive particles in a harmonic trap. Twisting the cavity out of the plane introduces a geometric phase for photons in the cavity waist, and the resulting photon modes can be mapped onto Landau levels. By transporting an ensemble of cold rubidium atoms to the cavity waist, we hybridize the cavity photons with atomic Rydberg excitations to create polaritons with strong interactions at the level of single quanta. Modulating the excited state allows us to observe the interaction induced quantum dynamics in a multimode resonator showing the building block for studying quantum manybody physics. Combining these capabilities, we can create a photonic Laughlin state in a curved manifold. We characterize the properties of manybody states by measuring the correlation between different spatial modes. This setup also allows us to use novel dissipative pumping to realize a chemical potential for photons and stabilize the manybody system. [Preview Abstract] 

E01.00126: Synthetic topological matter with ultracold fermions in optical lattices Zejian Ren, Bo Song, Chengdong He, Elnur Hajiyev, Qianhang Jerry Cai, GyuBoong Jo Ultracold atoms in optical lattices provide a versatile platform to explore topological physics. In this poster, we present a set of experiments on spinorbit coupled ytterbium fermions in bulk and in lattice, in which the band topology can be engineered on demand. Firstly, a novel symmetryprotected topological phase for ultracold fermions is realized in a Ramandressed onedimensional optical lattice. The topological invariant is measured in equilibrium across the topological phase transition, and the topological nature is further investigated in the spinrelaxation dynamics in nonequilibrium. Next, we report a new implementation of twodimensional (2D) spinorbit coupling in lattice resulting in 2D semimetal band structure. The tunable band topology is probed by the spin polarization measured within the first Brillouin zone. The semimetal behaviour is probed by measuring spin textures at different temperatures, showing an asymmetric quasimomentum distribution when the Fermi level is properly tuned. Our work will further broaden our knowledge of the novel spinorbit coupling (SOC) physics and pave the way to realization of the synthetic SOCs in a controlled manner. [Preview Abstract] 

E01.00127: Measuring topology by dynamics: Chern number from linking number Christof Weitenberg, Matthias Tarnowski, F. Nur Ünal, Nick Fläschner, Benno S. Rem, André Eckardt, Klaus Sengstock Topology plays an important role in modern solid state physics describing intriguing quantum states such as topological insulators. It is an intrinsically nonlocal property and therefore challenging to access, often studied only via the resulting edge states. Here, we measure the topological index directly from the farfrom equilibrium dynamics of the bulk. We use the mapping of the Chern number to the linking number of dynamical vortex trajectories appearing after a quench to the Hamiltonian of interest. We thereby map out the topological phase diagram of quantum gases in optical lattices via a purely dynamical response. Such relations between two topological indices in static and dynamical properties could be also an important approach for exploring topology in the case of interactions. [Preview Abstract] 

E01.00128: Engineering Topology and Interactions in Superconducting Microwave Cavity Lattices Clai Owens, Aman LaChapelle, Brendan Saxberg, Ruichao Ma, David Schuster, Jonathan Simon We present our latest progress in developing a novel architecture for exploration of topological matter using lattices of superconducting microwave cavities coupled to Josephson junction qubits. We show how microwave photons can be engineered to experience magnetic fields and particleparticle interactions, allowing us access to topological phenomena such as the fractional quantum Hall effect. We employ seamless 3D microwave cavities all machined from a single block of high purity superconductor, along with YttriumIronGarnet (YIG) spheres magnetically biased below the critical field to break time reversal symmetry while still maintaining scalability and compatibility with the circuit QED toolbox. We then present our latest push towards coupling Josephson junction qubits to a cryocompatible superconducting lattice. [Preview Abstract] 

E01.00129: Search for the FFLO phase in the dimensional crossover of an imbalanced fermi gas Yi Jin, Eduardo Ibarra G.P., Jacob A. Fry, Anna L. Marchant, Melissa C. Revelle, Randall G. Hulet The exotic Fulde– Ferrell– Larkin– Ovchinnikov (FFLO) magnetized superconductor has never been conclusively observed. It fills a large region of the onedimensional (1D) phase diagram and is believed to occupy only a small region, if any, in 3D. The FFLO phase should be more robust, however, against quantum and thermal fluctuations in higher dimensions. These considerations motivated the proposal to search for FFLO near the 1D3D dimensional crossover\footnote{M. M. Parish et al. Phys. Rev. Lett. 99, 250403 (2007).}, which we have identified and characterized\footnote{M. C. Revelle et al. Phys. Rev. Lett. 117, 235301 (2016).}. Using a 2D optical lattice, we confine a spinimbalanced Fermi gas of $^6$Li to 1D tubes. We bring the system to the dimensional crossover by tuning the intertube tunneling rate and the interaction strength in the BECBCS crossover regime. Domain walls carrying the excess unpaired spins would constitute direct evidence for FFLO pairs. These are expected to become more visible in a 1D timeofflight expansion, which we induce with a bluedetuned laser beam. We report our progress. [Preview Abstract] 

E01.00130: Enhancing Antiferromagnetic Correlations of an Atomic Fermi Gas in a 3D Optical Lattice YaTing Chang, Danyel CavazosCavazos, TsungLin Yang, Zhenghao Zhao, Randall G. Hulet The FermiHubbard model provides crucial insights into strongly correlated fermionic systems. Despite its simplicity, an exact solution for more than a few particles remains an open question. Systems of ultracold atoms in optical lattices provide a way to address this challenge. For example, their interactions are remarkably tunable. We have previously realized the 3D FermiHubbard model and detected shortrange antiferromagnetic (AFM) spin correlations via Bragg scattering. However, to realize the long range ordered AFM phase we must reach at least 40\% lower temperatures. We have replaced the IR fiber laser used to produce the lattice in the previous experiment with an ultralow noise monolithic ring cavity laser in order to reduce heating by the laser intensity noise. We furthermore control our lattice depth with a servo loop whose bandwidth is set to be lower than the lattice frequency. We will report the status of these efforts to enhance AFM correlations. [Preview Abstract] 

E01.00131: New Frontiers in Fermionic Quantum Gas Microscopy Muqing Xu, Christie Chiu, Geoffery Ji, Anton Mazurenko, Maxwell Parsons, Marton KanaszNagy, Richard Schmidt, Fabian Grusdt, Annabelle Bohrdt, Eugene Demler, Daniel Greif, Markus Greiner Quantum gas microscopy of fermionic atoms allows siteresolved studies of quantum manybody states and dynamics of strongly correlated particles in the Hubbard Model. In our experiment we use digital mirror devices (DMDs) to control optical potentials at the siteresolved level and to implement a new cooling scheme based on entropy redistribution. This has allowed us to observe longrange antiferromagnetic order in a repulsively interacting Fermi gas of Li6 in a square optical lattice. The ordered state extends across the entire sample size of about 80 lattice sites and is detected from the spin correlation function and spin structure factor. We also holedope the system by adjusting the chemical potential and enter a regime where numerical methods become intractable. Furthermore, we create single holes on selected lattice sites with the DMDs to study hole dynamics in an antiferromagnetic environment. We will discuss our most recent progress towards the siteresolved detection of possible holonholon and spinonholon string configurations, which may emerge in the doped regime and could be a crucial ingredient for the mechanism of hightemperature superconductivity. [Preview Abstract] 

E01.00132: Implementing Majorana fermions in a coldatom honeycomb lattice with the textured pairing order parameter Ruizhi Pan, Dongling Deng, Charles Clark Recent studies in the realization of Majorana Fermion (MF) quasiparticles have focused on engineering the topological superconductivity by combining conventional superconductors and the spintextured electronic materials. We propose an effective model to create unpaired MFs at the honeycomb lattice edge by generalizing a 2dimensional topologically nontrivial Haldane model and introducing textured pairing order parameters. The core idea is to add both the spinsinglet and textured spintriplet superconducting pairings to the pseudospinstate dependent honeycomb lattice with broken TimeReversal Symmetry (TRS) and satisfy generalized "sweet spot" conditions like in the Kitaev chain model. In our model, the system has the gapped superconducting phase and gapless phase, each of which further bifurcates associated with zero or nonzero topological winding numbers. We claim that the gapped superconducting and gapless phases further divide the TRS broken class and effective Majorana zero modes will arise at edge in some phases. Our theoretical model and several concepts such as the textured pairing order parameter and the "strength" of TRS breaking may an play important role in the future research on implementing MFs with cold atoms in optical lattices. [Preview Abstract] 

E01.00133: A new apparatus for microscopic control of ultracold strontium Matthew Norcia, Aaron Young, Adam Kaufman We present progress towards a new experimental system that combines the capabilities afforded by alkaline earth atoms, optical tweezers and latticebased quantum gas microscopy. We aim to use bosonic and fermionic neutral strontium atoms to provide a rich system with wellcontrolled tunneling properties, multiple longlived electronic and spin states, and highfidelity site and stateresolved readout. By utilizing narrowlinewidth optical transitions in strontium, we expect to achieve rapid highfidelity groundstate cooling of atoms within tweezers, which can then be loaded in a statepreserving manner into an optical lattice to prepare arbitrary lowentropy states. We think that this system will have applications in quantum information science, both through extending the exploration of sampling problems, and through the simulation of condensed matter systems. [Preview Abstract] 

E01.00134: Towards quantum simulation of spin dynamics in frustrated systems Ippei Nakamura, Ryuta Yamamoto, Takeshi Fukuhara Ultracold atoms trapped in an optical lattice are an ideal platform to simulate quantum spin systems governed by the Heisenberg model. As the periodic potential formed by interference of laser beams is free from the defects inescapably existing in solidstate materials, and further, offers a welldefined twodimensional system, the optical lattice system is highly suited to study the nature of manybody physics under the geometrical frustration. The quantum gas microscope technique enables us to observe and manipulate individual spins in optical lattices\footnote{T. Fukuhara \textit{et al}., Nat. Phys. \textbf{9}, 235 (2013).}. By applying this technique to a triangular\footnote{C. Becker \textit{et al}., New J. Phys. \textbf{12}, 065025 (2010).} or kagome lattice\footnote{G.B. Jo \textit{et al}., Phys. Rev. Lett. \textbf{108}, 045305 (2012).}, both of which exhibit geometrical frustration, we aim to trace the dynamics of an (emergent) excitation, like a spinon, in the frustrated spin system. To this end, we have been developing an experimental setup of triangular optical lattice employing Rb atoms and to date, have generated a $^{87}$Rb BEC by evaporative cooling in a crossed optical dipole trap and succeeded in transferring the BEC into a triangular optical lattice. [Preview Abstract] 

E01.00135: Quantum simulation of ultrafast and quasiperiodic systems with ultracold strontium Shankari Rajagopal, Ruwan Senaratne, Toshihiko Shimasaki, Peter Dotti, David Weld This poster discusses experiments using degenerate strontium atoms for the quantum emulation of ultrafast dynamics and quasicrystals. Trapped atoms subjected to a timevarying force field are used to emulate the ultrafast response of bound electrons or nuclei exposed to the electric field of a pulsed laser. The simulator operates in regimes equivalent to those of ultrafast and strongfield pulsedlaser experiments, opening up a hitherto unexplored application of quantum simulation techniques and a complementary path towards investigating open questions in ultrafast science. Separately, we study the dynamical response of atoms in a quasiperiodic bichromatic lattice to rapid modulation of the phasonic degree of freedom. Such excitations are typically frozen out as strain in solidstate quasicrystals; these measurements thus represent a new spectroscopic probe of quasicrystals which is inaccessible to traditional experiments. [Preview Abstract] 

E01.00136: Quench dynamics of a onedimensional quantum manybody system Sooshin Kim, Alexander Lukin, Matthew Rispoli, Robert Schittko, Simon Weidinger, Michael Knap, Adam Kaufman, Eric Tai, Julian Leonard, Markus Greiner In general, the dynamics of a quantum manybody system represent a computational challenge due to the exponential scaling of the Hilbert space size with system size. Hence, there is great interest in developing easily solvable effective models that nonetheless still capture the essential properties of interest. In this work, we verify the applicability of Luttinger liquid theory for studying quantum quenches in onedimensional BoseHubbard chains by looking at the dynamics of particle number fluctuations. We provide experimental estimates for the Luttinger liquid parameter as a function of interactions in our system. [Preview Abstract] 

E01.00137: Microscopic measurements of dynamics in FermiHubbard and Ising systems Peter Schauss, Peter Brown, Debayan Mitra, Elmer GuardadoSanchez, Alexis Reymbaut, Simon Bergeron, Dominic Bergeron, Reza Nourafkan, AndreMarie Tremblay, Jure Kokalj, David Huse, Waseem Bakr The ability to probe and manipulate cold atoms in optical lattices at the atomic level using quantum gas microscopes enables quantitative studies of dynamics. While there are many welldeveloped theoretical tools to study manybody quantum systems in equilibrium, simulating their dynamics is challenging with available techniques. Approximate methods need to be benchmarked, creating an urgent need for measurements in model experimental systems. Here we present two such measurements. First, we present experiments that probe the relaxation of density modulations in the doped FermiHubbard model. This leads us to a hydrodynamic description that allows us to determine the conductivity. We observe bad metallic behavior that we compare to predictions from finitetemperature Lanzcos calculations and dynamical mean field theory. Second, we introduce a new platform to study the 2D quantum Ising model. By illuminating atoms in an optical lattice with light that excites them to a lowlying Rydberg state, we observe quench dynamics that leads to antiferromagnetic correlations. We compare the shorttime dynamics to results from a dynamical numerical linked cluster expansion. [Preview Abstract] 

E01.00138: Towards deployable atomic gravimeters for geophysics Zachary Pagel, Xuejian Wu, Bola S. Malek, Jordan Dudley, Philip Canoza, Holger Muller Many types of gravimeters are used in geophysics for gravity surveying, mineral prospecting, seismology and natural disaster monitoring. Atomic gravimeters use materwave interferometry, and are more accurate and have better longterm stability than gravimeters based on springs, superconducting coils or falling cubes. Since current atomic gravimeters are too complicated to operate outside a wellcontrolled laboratory, we have implemented an atom interferometer using only one laser diode and a pyramidal mirror, allowing for the instrument to be simple, compact and transportable. The pyramidal mirror is used to create a magnetooptical trap (MOT), and this reduces the number of incident laser beams on the MOT region to a single retroreflected beam. Operating as a gravimeter, we have achieved sensitivities of 6 \textmu m/s2/$\surd $Hz. To ensure better transportability and reliability, we are developing an upgraded pyramidbased atomic gravimeter. Our simple and transportable design will open up applications in geodesy and geology. [Preview Abstract] 

E01.00139: Recent Progress on atom interferometers inside a hollowcore fiber Zilong Chen, Mingjie Xin, Wui Seng Leong, ShauYu Lan 

E01.00140: Abstract Withdrawn We theoretically propose a strategy to simulate magnetic polarons with dipolar ultracold atoms confined in onedimensional doublewell superlattice. A spatial pseudospin mapping is used to induce an effective spin chain with the superlattice dipolar gas, and the defects in the effective spin chain is modelled by the holons and/or doublons in superlattice. We derived an effective Hamiltonian to describe the coupling between the defects and the effective spins, and demonstrate two types of polarons arising from the coupling between the defects and magnons, as well as from the coupling between defects and magnetic kinks. These two type of polarons exist in the weak and strong dipolar interaction regime, respectively. We also investigate the induced interaction between defects intermediated by the magnons and kinks. 

E01.00141: Hyperbolic and FlatBand Lattices in Circuit QED Alicia Kollar, Mattias Fitzpatrick, Andrew Houck After close to two decades of research and development, superconducting circuits have emerged as a rich platform for both quantum computation and quantum simulation. The unique deformability of coplanar waveguide microwave resonators enables realization of artificial photonic materials which cannot be made from ordinary atomic or ionic systems. We will present two such examples. First, we will show that periodic lattices in hyperbolic spaces of constant negative curvature can be produced on chip, in particular hyperbolic analogs of the kagome lattice. These lattices constitute artificial materials which exist in regions of extreme gravitation or in antide Sitter space, and display highly unusual band structures with gapped flat bands. Second, we will present a novel Euclidean lattice, called the heptagonpentagonkagome (HPK) lattice, which displays a flat band with a particularly large gap. Because this flat band is spectrally isolated and dispersionless, interactions are the dominant energy scale, enabling the study of strongly correlated, manybody photon states. We will explore the theoretical origin of this gapped flat band and show experimental results where we introduce effective photonphoton interactions via nonlinear materials such as NbTiN. [Preview Abstract] 

E01.00142: Probing an attractive Fermi lattice gas with measurements of doublon fraction W. Morong, L. Slattery, B. DeMarco While the BECBCS crossover has been extensively studied in the case of a harmonically trapped ultracold Fermi gas, the corresponding problem in an optical lattice has received less attention, despite its relevance to the physics of superconducting materials. We characterize this system by studying the fraction of atoms in doublyoccupied sites, or doublons, which are the primary excitation for large interactions. We show that even moderate interactions can cause the system to fail to equilibrate as the lattice is turned on. We also study the lifetime of doublons following an interaction quench. [Preview Abstract] 

E01.00143: A halfdegenerate optical resonator for coldatom interferometry Ranjita Chanu Sapam, Nicolas Mielec, Arnaud Landragin, Remi Geiger We present the analysis of a half degenerate optical resonator consisting of a lens located between two plane mirrors. This resonator was designed to support a large waist (cm) Gaussian beam for applications to precision inertial measurements based on large momentum transfer atom interferometry. We investigate the spatial profile of the resonating beam, and the optical gain for different beam size, and the influence of misalignments on the degeneracy of the cavity. FFT simulations show that aberrations and surface imperfections of the optics are the main contributors to spatial inhomogeneities of the resonating beam, which supports our experimental results. We also report the stability of this resonator locked to an ultrastable optical reference. [Preview Abstract] 

E01.00144: Atomchip Gravimeter with BoseEinstein Condensates Sven Abend, Martina Gebbe, Matthias Gersemann, Christian Schubert, Ernst M. Rasel Atom interferometry is a wellproven tool to measure inertial forces or fundamental constants with high accuracy. BoseEinstein condensates (BECs) or deltakick collimated (DKC) atoms present ideal sources for precise measurements due to their small spatial and momentum width. We generate such an ensemble in a miniaturized atomchip setup, where BEC generation and DKC can be performed fast and reliably. We present new results on our prototype atomchip gravimeter, which takes place in a volume of a onecentimeter cube and comprises an innovative fountain scheme to enhance the device's sensitivity. The relaunch mechanism consists of the combination of double Bragg diffraction with Bloch oscillations. Based on these methods we develop a next generation device capable of catching to stateoftheart gravimeters by using a highflux atomchipbased source. [Preview Abstract] 

E01.00145: Continuous motional sensing with highly dispersive medium PeiChen Kuan, Chang Huang, ShauYu Lan Current stateoftheart atomsbased motional sensors rely on measuring the firstorder Doppler shift of the atomic transition of singleparticles. By using Dopplersensitive detection methods, the population of atomic states and, therefore, the velocity of atoms can be measured precisely. On the contrary, here, we demonstrate a novel method of measuring the centerofmass motion of an atomic ensemble using the collective interference of light passing through the ensemble under the condition of electromagneticallyinducedtransparency (EIT). With the large enhancement of the dispersion in the EIT medium, we realize an atombased velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. This method has the advantages of high data rate and convenient detection of the interference phase of light over the conventional method of detecting the florescence of atoms and could lead to a new design of compact atomsbased motional sensors. [Preview Abstract] 

E01.00146: Twophoton transitions in cold caesium atoms confined in a hollowcore optical fiber Tahyun Yoon, Zhengdao Ding, Fereshteh Rajabi, Brian Duong, Cameron Vickers, Jeremy Flannery, Rubayet Al Maruf, Michal Bajcsy We present the results of our experimental studies of cascade and lambdatype twophoton transitions in lasercooled caesium atoms loaded inside a hollowcore photoniccrystal fibre. We investigate the enhancements of the twophoton processes by the tight confinement of the propagating light and from the slowlight effects arising in the optically thick atomic ensemble. We also explore the applications of these transitions for alloptical switching, crossphase modulation, and light storage. [Preview Abstract] 

E01.00147: Interacting Rydberg Polaritons for Photonic Quantum Logic Steffen SchmidtEberle, Daniel Tiarks, Thomas Stolz, Stephan D\"urr, Gerhard Rempe The strong dipoledipole interaction between Rydberg atoms has enabled remarkable experimental success ranging from quantum information processing with single atoms to observation of exotic manybody states. The interaction between Rydberg excitations can also be used to create a large effective interaction between photons. To this end, one addresses Rydberg states with electromagnetically induced transparency. This creates a quasiparticle, called Rydberg polariton, which consists of a photonic component and a copropagating atomic Rydberg excitation. The large interaction between the Rydberg components manifests itself in the form of a giant optical nonlinearity. A central goal in the field of Rydberg polaritons is the realization of photonic quantum logic. This line of research has seen impressive progress in the last few years, including the demonstration of singlephoton transistors and the observation of large conditional phase shifts at the single photon level. We describe our recent progress on using Rydberg polaritons for photonic quantum logic. [Preview Abstract] 

E01.00148: TwoQubit Optical Gate in a MixedSpecies TrappedIon Quantum Processor Colin Bruzewicz, Jonathon Sedlacek, Jules Stuart, Robert McConnell, Jeremy Sage, John Chiaverini Here we demonstrate an entangling MolmerSorensen (MS) gate between cotrapped $^{40}\mathrm{Ca}^{+}$ and $^{88}\mathrm{Sr}^{+}$ ions using electronic transitions to the ions’ metastable excited states. This interspecies quantum gate may find use in a largescale trappedion processor where one atomic species is used for highfidelity logic operations and the second auxiliary species is used for low crosstalk state readout and sympathetic motional cooling. The use of optical qubits in a $^{40}\mathrm{Ca}^{+}$ and $^{88}\mathrm{Sr}^{+}$ system is particularly appealing because the laser wavelengths that drive the MS interaction are in the visible portion of the spectrum. These wavelengths are compatible with lowloss photonic waveguides that can be integrated directly into the multilayer structure of a microfabricated iontrapchip. As demonstrated previously in our group in a separate experiment, integrated waveguides can be used to route laser beams to the ion locations without the need for bulk freespace optics, potentially enabling more sophisticated iontrapping geometries. [Preview Abstract] 

E01.00149: Cubic Nonlinearity of WS$_{\mathrm{2}}$ Nanoflakes Tikaram Neupane, Dulitha Jayakodige, Bagher Tabibi, Felix Jaetae Seo The cubic nonlinearity of tungsten disulfide atomic layers is of great interest for optical power limiting and saturable Qswitching. The nonlinear optical properties of tungsten disulfide nanoflakes in aqueous solution was characterized with Zscan technique with resonant at 532 nm with 6 ns pulse width and 10 Hz repetition rate. The absorption spectrum of WS$_{\mathrm{2}}$ nanoflake mixtures of one to four atomic layers in aqueous solution shows the characteristic A, B, and C peaks. The A and B absorption bands are due to the large band spitting of conduction band with strong coupling between electron spin and delectron orbital coupling, and the C band is due to the band nesting by the singularity of joint density of state. The nonlinear absorption and nonlinear refraction coefficients of WS$_{\mathrm{2}}$ nanoflakes were estimated to be \textasciitilde 6.2 x 10$^{\mathrm{4}}$ cm/GW with open Zscan, and \textasciitilde 0.9 x 10$^{\mathrm{10}}$ cm$^{\mathrm{2}}$/W with closed Zscan. Acknowledgment: This work is supported by ARO W911NF1510535, NSF HRD1137747, and NASA NNX15AQ03A. [Preview Abstract] 

E01.00150: Selfphase Modulation of MoS$_{\mathrm{2}}$ Nanoflakes Tikaram Neupane, Dulitha Jayakodige, Bagher Tabibi, Felix Jaetae Seo The thirdorder nonlinear optical property of molybdenum disulfide (MoS$_{\mathrm{2}})$ atomic layers was characterized by the spatial selfphase modulation (SSPM) which arises from an intensitydependent refractive index change. The diffraction ring of SSPM was distorted along the vertical direction after the MoS$_{\mathrm{2}}$ nanoflakes was exited by a laser pulse at 532 nm, \textasciitilde 6 ns temporal pulse width, and 10 Hz repetition rate. The nonlinear refractive index and the thirdorder susceptibility was estimated a series of concentric circles of SSPM diffraction ring patterns. The nonlinear refractive index and the thirdorder susceptibility of MoS$_{\mathrm{2}}$ nanoflakes were estimated to be \textit{\textasciitilde }2.09 x 10$^{\mathrm{10}}$\textit{ cm}$^{2}/W$ and \textasciitilde 1.68x10$^{\mathrm{16}} \quad m^{2}/V^{2}$ respectively at the peak intensity \textasciitilde 0.3\textit{GW/cm}$^{2}$. Acknowledgment:~This work is supported by ARO W911NF1510535, NSF HRD1137747, and NASA NNX15AQ03A [Preview Abstract] 
(Author Not Attending)

E01.00151: Spin correlations between individual colliding atomic pair Eyal Schwartz We experimentally study spin2 dynamics between two colliding individual~85Rb~atoms,~trapped in tight optical tweezers.~The two colliding 85Rb atoms have effective attractive interactions that are not favorable for collision experiments using ultracold gases. Observing the individual pairs also allow for direct investigation of correlation between the magnetic substates of the two atoms, who keeps perfect correlation throughout our second long experiment times. Contrary to both finite temperature manybody experiments and zerotemperature twobody experiments, our finite temperature twobody experiments show relaxation dynamics rather than coherent spinwaves. Our experiments indicate that spinexchange collisions may also provide a useful entanglement mechanism at finite temperatures, which will be less prone to heating during an experiment. [Preview Abstract] 

E01.00152: Making Pb look like Au via coherent control: Shaping driving laser pulses to induce an arbitrary HHG spectra Denys Bondar, Andre Campos, Renan Cabrera, Herschel Rabitz We show that a laser pulse can always be found that induces a desired optical response (i.e., high harmonic generation  HHG) from an arbitrary physical systems. As illustrations, driving fields are computed to induce the same HHG from a variety of distinct systems (open and closed, quantum and classical). These results may be viewed as realizing an aspect of the alchemist dream to make different elements or materials look alike, albeit for the duration of a control laser pulse. The developed approach reveals unexplored flexibilities of nonlinear optics that may have many implications: The observed induced dipolar spectra without detailed information on the driving field turns out not to be sufficient to characterize atomic and molecular systems. The constructed approach may also be applied to design materials with specified optical characteristics. The ability to control nonlinear optical response may enable to discriminate nearly identical quantum systems. The latter problem is inspired by the challenges in the life sciences. [Preview Abstract] 

E01.00153: Apparatus for study of spatially periodic density variations in optical molasses Patrick Connolly, Timothy Roach We have developed a system to study large (mm) scale spatially periodic density variations in laser cooled atoms. The atoms are collected either in an optical molasses or a weak magnetooptic trap, in a conventional 6 beam configuration (three orthogonal pairs of nearly counterpropagating laser beams). Three video cameras provide views of atomic fluorescence along approximately orthogonal axes, so that the 3D spatial structure of the atomic cloud can be discerned. One camera view is nearly collinear with a laser beam; the other two are at 45° to laser beams. Fourier transforms of 2D images are used to quantify the periodicity. For simple 1D patterns, the observed periods scale ~lambda/sine(theta), where theta is angle of a nearly counterpropagating pair, relative to 180°. Differential screw mirror mounts give ~0.2mrad control of the relative angles for all three beam pairs so that 2D and 3D patterns can be produced and investigated. [Preview Abstract] 

E01.00154: Towards multilevel quantum logic with trapped ions Brendan Bramman, Pei Jiang Low, Richard Rademacher, Crystal Senko We report on progress developing tools to control ddimensional quantum systems (qudits) encoded in the hyperfine structure of trapped atomic ions. The welldeveloped toolbox for manipulating ionic qubits can be modified to extend to coherent control of single and twoqudit operations and measurement capabilities to obtain full information on the qudit state. Such a system could be useful either for quantum computing, offering potential scaling advantages, or for quantum simulations of higherdimensional systems such as interacting integer spin chains. [Preview Abstract] 

E01.00155: A dualspecies trapped ion quantum simulator for studying quantum dynamics of large number of spins Nikhil Kotibhaskar, Sainath Motlakunta, ChungYou Shih, Nikolay Videnov, Ilango Maran, Kaleb Ruscitti, Fereshteh Rajabi, Rajibul Islam Long decoherence times, high fidelity initialization and detection of qubit states, and the flexibility to engineer various types of interactions make trapped ions an ideal platform for quantum computation and simulation. Here, we report on our progress towards developing a Yb+/Ba+ dual species quantum simulator for studying manybody quantum Hamiltonians with a large number of Yb+ spins or qubits. The Ba+ ions will be used for sympathetic cooling and will take part in collective vibrational states that mediate spinsspin interactions. We optimize our system for 50100 spins, where classical computation of quantum spin dynamics may become intractable. We engineer the simulator to be scalable and robust. For example, most of the laser beams will be combined and delivered to the ion chain along their axial direction through a single photonic crystal fiber, drastically simplifying the optics and efficiently using optical power in a scalable way. High numerical aperture (up to NA= 0.5) optical access for the imaging setup will allow for fast and high fidelity spin state detection. The high NA setup will also allow high fidelity quantum operations by precise optical engineering of the coherent Raman beams using a spatial light modulator. [Preview Abstract] 

E01.00156: Superradiant lasing on the millihertz clock transition Julia Cline, Matthew Norcia, Robert LewisSwan, Juan Muniz, Bihui Zhu, John Robinson, Ross Hutson, Akihisa Goban, G. Edward Marti, Jun Ye, Ana Rey, James Thompson We demonstrate that superradiant laser light emitted from an ultranarrow transition can serve as a highly accurate and stable active atomic frequency reference. We present frequency comparisons between superradiant light emitted from the 1~mHz linewidth optical clock transition in $^{87}$Sr and a state of the art stable laser system and optical lattice clock [Norcia \textit{et. al.} arXiv:1711.10407]. We characterize the stability and absolute accuracy of the superradiant system and demonstrate insensitivity to key environmental perturbations. Additionally, we present our observations of spinexchange interactions mediated by the emission and reabsorption of photons inside an optical cavity [Norcia \textit{et. al.} arXiv:1711.03673]. We observe the emergence of a manybody energy gap and signatures of gap protection of the optical coherence against dephasing. Finally, we present future prospects for a continuous superradiant laser. [Preview Abstract] 

E01.00157: Precision measurement and fewbody physics with latticetrapped Fermidegenerate gases of strontium Ross B. Hutson, Akihisa Goban, G. Edward Marti, Sara L. Campbell, Michael A. Perlin, Jose P. D'Incao, Paul S. Julienne, Ana Maria Rey, Jun Ye We implement high resolution clock spectroscopy and spatially resolved readout of Fermidegenerate strontium in a threedimensional optical lattice. Here, correlations in the atomic signal between different spatial regions of the sample enable the most rapid evaluation of lattice induced clock shifts and a record fractional frequency precision of $2.5 \times 10^{19}$. Additionally, spectrally resolved interactions enable us to isolate $n$atom lattice sites, where we observe the onset of multibody interactions as both a densitydependent clock shift that is nonlinear in the occupationnumber, and threebody recombination loss. Furthermore, careful characterization of the lattice potential enables a precise extraction of the two and threebody interaction parameters. In future work, these techniques can be directly applied to tests of general relativity at the millimeter scale and studies of magnetic correlations in largespin quantum materials. [Preview Abstract] 

E01.00158: Towards a Molecular Lattice Clock: MagicWavelength Vibrational Spectroscopy of Sr$_{\mathrm{2}}$ Kon H. Leung, ChihHsi Lee, Stanimir Kondov, Christian Liedl, Tanya Zelevinsky Homonuclear diatomic molecules tightly confined at ultracold temperatures allow for highprecision spectroscopy and coherent control over their quantum states. These qualities offer novel pathways for tests of fundamental physics, such as searches for temporal drifts in the fundamental constants and ``fifth forces'', in addition to probing quantum chemistry in the ultracold regime. Here we report the progress in building a molecular lattice clock with ultracold $^{\mathrm{88}}$Sr$_{\mathrm{2}}$ molecules trapped in an optical lattice, with the goals of testing molecular QED, improving constraints on nanometerscale gravity, and potentially providing a modelindependent test of the temporal variation of the electronproton mass ratio. These involve precise metrology of the binding energies of vibrational states spanning the groundstate potential. We locate several vibrational states by employing twophoton spectroscopy. To eliminate differential light shifts and decoherence due to the lattice, we demonstrate a new type of magic wavelength based on narrow polarizability resonances. Additionally, we present results on ultracold photodissociation where we demonstrate magnetic field control of matterwave interference in the emerging photofragment angular distributions, and probe the quantumquasiclassical transition behavior at increasing photofragment energies, finding excellent agreement with a multichannel quantum chemistry model. [Preview Abstract] 

E01.00159: Two $^{87}$Sr lattice clocks with $10^{17}/\sqrt{\tau}$ level stability Lindsay Sonderhouse, Eric Oelker, Tobias Bothwell, Ross Hutson, Colin Kennedy, Edward Marti, Dhruv Kedar, Akihisa Goban, Sarah Bromley, Sara Campbell, John Robinson, William Milner, Shimon Kolkowitz, Christian Sanner, Dan Matei, Thomas Legero, Fritz Riehle, Uwe Sterr, Jun Ye Optical lattice clocks have reached unprecedented precision by interrogating highQ optical transitions with thousands of atoms simultaneously. The stability of optical lattice clocks is generally limited by the Dick effect, aliasing of the local oscillator's frequency noise. I detail the use of a laser stabilized to a 124 K silicon cavity to improve the stability of the JILA 1D and 3D $^{87}$Sr lattice clocks. The laser has a thermalnoiselimited stability of mod$\sigma = 4\times10^{17}$, the current world record. Selfcomparisons within each clock and asynchronous comparisons between the clocks demonstrate mid$10^{17}/\sqrt{\tau}$ stability for the 1D clock, and high$10^{17}/\sqrt{\tau}$ stability for the 3D clock. The 1D result is a record stability for a laser locked to a single atomic clock. I also discuss efforts to further improve the stability of the 3D clock by reducing its dead time. [Preview Abstract] 

E01.00160: Towards an order of magnitude improved sensitivity to the electron's EDM with trapped HfF$^{\mathrm{+}}$ William B. Cairncross, Tanya S. Roussy, Daniel N. Gresh, Kia Boon Ng, Jeffrey Meyers, Kevin Boyce, Yan Zhou, Yuval Shagam, Jun Ye, Eric A. Cornell In 2017, our group completed the first measurement of the electron's electric dipole moment (eEDM, $d_{e})$ using trapped molecular ions, yielding a 90{\%} confidence upper bound of \textbar $d_{e}$\textbar \textless 1.3 x 10$^{\mathrm{28}} \quad e$ cm. Our measurement [1], which was statisticslimited, provided confirmation of the upper bound on \textbar $d_{e}$\textbar set by the ACME Collaboration [2], and demonstrated coherence times over 1 second using trapped molecules  a valuable feature for future eEDM searches. Here, we will present our progress towards an order of magnitude higher statistical sensitivity via increased sample size and coherence time, cooling of the rotational degree of freedom, and imaging of photodissociation products. [1] W. B. Cairncross \textit{et al}., Phys. Rev. Lett. \textbf{119}, 153001 (2017) [2] The ACME Collaboration, Science \textbf{343}, 269 (2014) [Preview Abstract] 

E01.00161: Measurement of the Rydberg constant with cold Rydberg atoms Ryan Cardman, Andira Ramos, Georg Raithel Progress in precision measurement of the Rydberg constant using microwave spectroscopy of cold Rydberg atoms is discussed. Rydberg atoms in circular states, i.e., in highorbitalangularmomentum energy levels, have toroidal wave functions. This diminishes energy shifts brought on by the overlap of the valence electron wave function with the ion core, and eliminates QED effects and effects of the nuclear charge distribution on spectroscopic measurements, offering a value of the Rydberg constant decoupled from effects of the proton radius puzzle. In this poster, we describe the twophoton microwave transition from a circular Rydberg state of principal quantum number n to a nearcircular state of principal quantum number n+2. The atoms are initially prepared in an optical molasses, laserexcited into an Fstate using a threestep excitation, and circularized. We also present details on the microwave horn system that emits subTHz microwaves into the apparatus to drive the transitions. The atom distribution between initial (circular) and final (nearcircular) Rydberg states is analyzed using stateselective field ionization. The expected systematic uncertainties of the measurement are discussed. [Preview Abstract] 

E01.00162: Precision Contrast Interferometry with Yb BoseEinstein condensates for $h/m$ and $\alpha$ Daniel Gochnauer, Katherine McAlpine, Benjamin PlotkinSwing, Subhadeep Gupta Our ytterbium (Yb) BoseEinstein condensate (BEC) contrast interferometer operates with standingwave light pulses and is designed to make a precision measurement of the fine structure constant, $\alpha$, via a direct measurement of $h/m$, where $h$ is the Planck constant and $m$ is the mass of Yb. The interferometer signal is insensitive to both magnetic fields, due to the nonmagnetic Yb ground state, and mirror vibrations, due to the symmetry of the interferometer arms. We have recently extended this approach to momentum separation as large as $112$ photon recoils between outer paths [1]. The interferometer phase evolution is quadratic with number of recoils, reaching a rate as high as $7\times10^7$ radians/s. Furthermore, we suppress undesired diffraction phases through careful choosing of and precise control over our atom optics parameters. We will discuss our theoretical model for these phases and compare to experimental results for various pulse parameters. The observed performance at large momentum separation indicates a favorable scaling of the interferometer towards a precision measurement of $\alpha$.\\\text{[1]} B. PlotkinSwing et al, arXiv:1712.06738 [Preview Abstract] 

E01.00163: Status and the Future of HAYSTAC: Quantum Enhancement of a Dark Matter Axion Search Maria Simanovskaia Dark matter axions may be detected by their resonant conversion to photons in a tunable microwave cavity permeated by a strong magnetic field. The Haloscope at Yale Sensitive To Axion Cold dark matter (HAYSTAC) is the first such axion cavity detector to incorporate a dilution refrigerator and Josephson parametric amplifier and thereby achieve nearquantumlimited noise performance. Last year, first results from HAYSTAC excluded axion models a factor of $\sim$2.3 above the benchmark KSVZ model over the mass range 23.55 $\mu$eV $< m_a <$ 24.0 $\mu$eV. These are the first limits within the axion model band in the 10100 $\mu$eV mass decade. As both a testbed for innovative cavity and amplifier concepts and a data pathfinder, HAYSTAC is constantly pushing the sensitivity limits and achievable frequency ranges of axion cavity detectors. I will discuss the current state of HAYSTAC and our ongoing research and development work including novel cavity designs and incorporation of recent developments in quantum measurement technology to circumvent the standard quantum limit, thus greatly improving the search rate and sensitivity of the experiment. [Preview Abstract] 
Follow Us 
Engage
Become an APS Member 
My APS
Renew Membership 
Information for 
About APSThe American Physical Society (APS) is a nonprofit membership organization working to advance the knowledge of physics. 
© 2019 American Physical Society
 All rights reserved  Terms of Use
 Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 207403844
(301) 2093200
Editorial Office
1 Research Road, Ridge, NY 119612701
(631) 5914000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 200452001
(202) 6628700