Bulletin of the American Physical Society
APS March Meeting 2016
Volume 61, Number 2
Monday–Friday, March 14–18, 2016; Baltimore, Maryland
Session V31: Plasmonics and Beyond III: Materials and StructuresFocus
|
Hide Abstracts |
Sponsoring Units: DCP Chair: F. Javier Garcia de Abajo, Barcelona Institute of Science Room: 331 |
Thursday, March 17, 2016 2:30PM - 2:42PM |
V31.00001: Three-dimensional topological insulator based nanospaser Hari Paudel, Vadym Apalkov, Mark Stockman After the discovery of spaser, now it has been possible to deliver optical energy beyond the diffraction limit and generate an intense source of optical field. Spaser is a nanoplasmonic counter part of laser. One of the major advantages of spaser is the size: spaser is truly a nanoscopic device whose size can be made smaller than skin depth of the material to a size as small as the nonlocality radius. Recently, an electrically pumped graphene based nanospaser has been prosposed that operates in the mid-infrared frequency (Apalkov {\&} Stockman). Here we propose an optically pumped nanospaser based on 3-dimensional topological insulator (3D TI) materials such as Bi2Se3 that operates at an energy equal to the bulk bandgap energy and uses the surface as a source for plasmons and its bulk as a gain medium. The population inversion is obtained in the bulk and radiative energy of exciton recombination is transferred to surface plasmons of the same material to stimulate spasing action. As this spaser operates in the mid-infrared spectral region, it can be a useful devices for number of applications such as nanoscopy, nanolithography, nanospectroscopy, and semi-classical information processing. [Preview Abstract] |
Thursday, March 17, 2016 2:42PM - 2:54PM |
V31.00002: Light Scattering by Spheroids Ya-Ming Xie, Xia Ji Nowadays, with the development of technology, particles with size at nanoscale have been synthesized in experiments. It is noticed that anisotropy is an unavoidable problem in the production of nanospheres. Besides, nonspherical nanoparticles have also been extensively used in experiments. Comparing with spherical model, spheroidal model can give a better description for the characteristics of nonspherical particles. Thus the study of analytical solution for light scattering by spheroidal particles has practical implications. By expanding incident, scattered, and transmitted electromagnetic fields in terms of appropriate vector spheroidal wave functions, an analytic solution is obtained to the problem of light scattering by spheroids. Unknown field expansion coefficients can be determined with the combination of boundary conditions and rotational-translational addition theorems for vector spheroidal wave functions. Based on the theoretical derivation, a Fortran code has been developed to calculate the extinction cross section and field distribution, whose results agree well with those obtain by FDTD simulation. [Preview Abstract] |
Thursday, March 17, 2016 2:54PM - 3:06PM |
V31.00003: Optical response of metal nanojunctions driven by single atom motion: influence of quantized electron transport on nanoplasmonics Daniel Sanchez-Portal, Federico Marchesin, Peter Koval, Marc Barbry, Javier Aizpurua The correlation between transport properties across sub-nanometric metallic gaps and the optical response of the system is a complex effect that, similarly to the near-field enhancement [1], is determined by fine atomic-scale details in the junction structure. Using ab initio calculations, we present here a study of the simultaneous evolution of the structure and the optical response of a plasmonic junction as the two Na$_\{380}$ clusters forming the cavity approach and retract. Atomic reorganizations are responsible for a large hysteresis of the optical response. The system exhibits a jump-to-contact instability during the approach, and the formation of an atom-sized neck across the junction during retraction. Due to the quantization of the conductance in metal nanocontacts, atomic-scale reconfigurations play a crucial role in determining the optical response. We observe abrupt changes in the intensities and spectral positions of the dominating plasmon resonances, and find a one-to-one correspondence between these jumps and those of the quantized transport across the neck. These results point out to an unforeseen connection between transport and optics at the atomic scale, which is at the frontier of current optoelectronics. [1] M. Barbry, et al., Nano Letters 354, 216 (2015) [Preview Abstract] |
Thursday, March 17, 2016 3:06PM - 3:42PM |
V31.00004: Condensed Matter in Ultrafast and Superstrong Fields: Attosecond Phenomena Invited Speaker: Mark Stockman We present our latest results for a new class of phenomena in condensed matter optics when a strong optical field ~1-3 V/Å changes a solid within optical cycle [1-7]. Such a pulse drives ampere-scale currents in dielectrics and adiabatically controls their properties, including optical absorption and reflection, extreme UV absorption, and generation of high harmonics [8] in a non-perturbative manner on a 100-as temporal scale. Applied to a metal, such a pulse causes an instantaneous and, potentially, reversible change from the metallic to semimetallic properties. We will also discuss our latest theoretical results on graphene that in a strong ultrashort pulse field exhibits unique behavior [9, 10]. New phenomena are predicted for buckled two-dimensional solids, silicene and germanine [11]. These are fastest phenomena in optics unfolding within half period of light. They offer potential for petahertz-bandwidth signal processing, generation of high harmonics on a nanometer spatial scale, etc.\\ References\\ [1] M. Durach et al., Phys. Rev. Lett. 105, 086803 (2010). [2] M. Durach et al., Phys. Rev. Lett. 107, 086602 (2011). [3] A. Schiffrin et al., Nature 493, 70 (2013). [4] M. Schultze et al., Nature 493, 75 (2013). [5] V. Apalkov, and M. I. Stockman, Phys. Rev. B 88, 245438 (2013). [6] V. Apalkov, and M. I. Stockman, Phys. Rev. B 86, 165118 (2012). [7] F. Krausz, and M. I. Stockman, Nat. Phot. 8, 205 (2014). [8] T. Higuchi, M. I. Stockman, and P. Hommelhoff, Phys. Rev. Lett. 113, 213901 (2014). [9] H. K. Kelardeh, V. Apalkov, and M. I. Stockman, Phys. Rev. B 90, 085313 (2014). [10] H. K. Kelardeh, V. Apalkov, and M. I. Stockman, Phys. Rev. B 91, 045439 (2015). [11] H. K. Kelardeh, V. Apalkov, and M. I. Stockman, Phys. Rev. B 92, 045413 (2015). [Preview Abstract] |
Thursday, March 17, 2016 3:42PM - 3:54PM |
V31.00005: Nobel metal alloyed thin-films with optical properties on demand Chen Gong, Marina S. Leite Metallic materials with tunable optical responses can enable the unprecedented control of optoelectronic and nanophotonic devices with enhanced performance, such as thin-film solar cells, metamaterials and metasurfaces for tunable absorbers and optical filters, among others. Here we present the alloying of noble metals, Ag, Au and Cu, to develop a novel class of material with optical response not achieved by pure metals. We fabricate binary mixtures with controlled chemical composition by co-sputtering. Ellipsometry and surface plasmon polariton coupling angle measurements are in excellent agreement when determining the real part of the dielectric function ($\varepsilon $1). Surprisingly, in some cases, a mixture provides a material with higher surface plasmon polariton quality factor than the corresponding pure metals. Our approach paves the way to implement metallic nanostructures with tunable absorption/transmission, overcoming the current limitation of the dielectric function of noble metals. [Preview Abstract] |
Thursday, March 17, 2016 3:54PM - 4:06PM |
V31.00006: Metal alloyed nanostructures with tunable optical properties. Mariama Rebello Sousa Dias, Chen Gong, Garrett Wessler, Marina Leite Pure metal nanostructures (Ns) have been widely used to enhance the optical response of optoelectronic devices, ranging from photovoltaics to broadband absorbers. However, their use is limited by their fixed optical properties. The development of metallic materials with modulated optical response could lead to a new class of Ns for optoelectronic devices with enhanced performance. In this work, we simulated and measured the optical response of binary mixtures of silver (Ag), gold (Au) and aluminum (Al) nanoparticles. We resolved the broadband forward scattering of these alloyed nanoparticles when applied to solar cells by finite-difference time-domain (FDTD) calculations. For a realistic prediction, we used the measured dielectric function of thin-films with identical chemical composition. We demonstrate that, in some cases, an alloy can outperform their pure metal counterparts, $e.g.$ Ag$_{\mathrm{0.5}}$Au$_{\mathrm{0.5}}$ shows increased light absorption at 800 nm than pure Au and Ag. The optical response of the alloyed Ns and its dependence with size and composition is measured by transmission and near-field scanning optical microscopy (NSOM). The use of alloyed metals as building blocks for broadband absorbers, where a large imaginary part of the dielectric function is desired, will also be discussed. [Preview Abstract] |
Thursday, March 17, 2016 4:06PM - 4:18PM |
V31.00007: Emission and propagation of hyperbolic phonon polaritons in hexagonal boron nitride Siyuan Dai, Qiong Ma, Yafang Yang, Jeremy Rosenfeld, Michael Goldflam, Alex McLeod, Trond Andersen, Zhe Fei, Mengkun Liu, Zhiyuan Sun, Yinming Shao, Kenji Watanabe, Takashi Taniguchi, Mark Thiemens, Fritz Keilmann, Pablo Jarillo-Herrero, Michael Fogler, D. N. Basov Using scattering-type scanning near-field optical microscope (s-SNOM), we studied various kinds of emission and propagation of hyperbolic phonon polaritons (HP2s) in hexagonal boron nitride (hBN). The systematic study via real-space nano-imaging reveals the emission mechanisms and propagating properties of HP2s excited by crystal edges, artificial structures, surface defects and impurities. Compared with traditional s-SNOM tip emitter, the polaritons from new emitters reported in this work possess longer propagation length and can be artificially manipulated on the hBN surface. Our work may benefit the future applications and engineering of HP2s using convenient emitters which are analogous to collective modes in other materials. [Preview Abstract] |
Thursday, March 17, 2016 4:18PM - 4:54PM |
V31.00008: Nano-photonic phenomena in van der Waals atomic layered materials Invited Speaker: Dmitri Basov Layered van der Waals (vdW) crystals reveal diverse classes of light-matter modes (polaritons) including: surface plasmon polaritons in graphene, hyperbolic phonon polaritons in boron nitride, exciton polaritons in MoS2, Cooper pair plasmon polaritons in high-Tc cuprates, topological plasmon polaritons and many others. Polaritons in vdW materials are of considerable technological interest. For example, polaritonic modes enable sub diffractional focusing and imaging in infrared frequencies. Applications apart, infrared nano-imaging of propagating polaritons facilitates experimental access to new physics of vdW materials not attainable with conventional spectroscopic methods. I will discuss two recent experiments performed in our group that utilize unique virtues of polaritons. Nano-imaging of plasmon polaritons in moire superlattices formed in graphene on boron nitride has allowed us to establish the important features of the electronic structure of this interesting from of graphene. Pump-probe hyper-spectral images of non-equilibrium plasmon polaritons in graphene revealed novel aspects of carrier relaxation. [Preview Abstract] |
Thursday, March 17, 2016 4:54PM - 5:30PM |
V31.00009: Unveiling nanometric plasmons optical properties with advanced electron spectroscopy in the Scanning Transmission Electron Microscope Invited Speaker: Mathieu Kociak Since the pioneering work of Yamamoto[1], the use of electron spectroscopy such as Cathodoluminescence (CL) and Electron Energy Loss Spectroscopy (EELS) in a Scanning (Transmission) Electron Microscope (STEM) has considerably helped improving our understanding of the optical properties of metallic nanoparticles. The resemblance of spectroscopic signals from electron and pure optical techniques leads to the intuition that both types of techniques are very close, an idea theoretically discussed by F.J. Garcia de Abajo and coworkers[2]. However, it is also quite intuitive that CL and EELS should be different. For example, EELS helps detecting any sort of modes while CL can only detect radiative ones. On the other hand, even between optical spectroscopy techniques, clear differences such as energy shifts or spectral shapes changes are expected in the case of plasmons. The lack of adapted instrumentation capable of performing combined EELS and CL, as well as theoretical developments allowing to account for the generic difference between EELS and CL and their optical counterparts impeached a comprehensive understanding of plasmons physics with the otherwise amazing electron spectroscopies. In this talk, I will present recent experimental results showing combined EELS and CL spectral mapping of plasmonic properties for nanoparticles with several shapes (triangles [3], cubes, stars…) and composition (gold, silver, aluminum…). Helped with different theoretical tools [3,4], I will try to show how these results can be related to their optical counterparts (extinction, scattering), and what type of physical insights can be gained from these combined measurements. Finally, if time allows, pointing the weaknesses of state-of-the-art CL and EELS (in terms of spectral range and/or spectral resolution), I will present EELS results obtained on highly monochromated electron beams that could cope with these limitations. [1] N. Yamamoto, K. Araya, and F. García de Abajo, Phys. Rev. B 64, (2001). [2] F. García de Abajo and M. Kociak, Phys. Rev. Lett. 100, (2008). [3] A. Losquin, L. F. Zagonel, V. Myroshnychenko, B. Rodríguez-González, M. Tencé, L. Scarabelli, J. Förstner, L. M. Liz-Marzán, F. J. G. de Abajo, O. Stéphan, and M. Kociak, Nano Lett. 15, 1229 (2015). [4] A. Losquin and M. Kociak, ACS Photonics 2, 1619 (2015). [Preview Abstract] |
Thursday, March 17, 2016 5:30PM - 5:42PM |
V31.00010: GaAs/InAs quantum dot exciton and trion excitation via nearby plasmonic waveguides Matt seaton, Yanwen Wu, Dan Gammon, Allan Bracker An open area of research in quantum plasmonics is the detailed characterization of the interaction between plasmonic structures and single quantum emitters. We observe the indirect excitation of excitons and trions in MBE grown GaAs/InAs quantum dots embedded in a Schottkey structure by nearby plasmons. The samples, grown on heavily doped N-type GaAs, were coated with a thin Cr layer to provide an electrical gate, through which we observe the photoluminescence spectrum of the different exciton charge states. Through spatially resolved photoluminescence spectroscopy, we verify the QD signature by laser pumping of surface plasmons in Ag thin film plasmonic waveguides near the dots. The waveguides were lithographically defined and embedded in the QD layer of the substrate via wet chemical etching and thermal vapor deposition. The characteristic PL spectra of the dots were collected and observed a large distance away from the excitation point, on the order of ten microns. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700