DOCSLIB.ORG

Polariton-Driven Phonon Laser

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Polariton-Driven Phonon Laser ARTICLE https://doi.org/10.1038/s41467-020-18358-z OPEN Polariton-driven phonon laser D. L. Chafatinos 1, A. S. Kuznetsov2, S. Anguiano1, A. E. Bruchhausen1, A. A. Reynoso1, K. Biermann2, ✉ P. V. Santos 2 & A. Fainstein 1 Efficient generation of phonons is an important ingredient for a prospective electrically-driven phonon laser. Hybrid quantum systems combining cavity quantum electrodynamics and optomechanics constitute a novel platform with potential for operation at the extremely high frequency range (30–300 GHz). We report on laser-like phonon emission in a hybrid system 1234567890():,; that optomechanically couples polariton Bose-Einstein condensates (BECs) with phonons in a semiconductor microcavity. The studied system comprises GaAs/AlAs quantum wells coupled to cavity-confined optical and vibrational modes. The non-resonant continuous wave laser excitation of a polariton BEC in an individual trap of a trap array, induces coherent mechanical self-oscillation, leading to the formation of spectral sidebands displaced by harmonics of the fundamental 20 GHz mode vibration frequency. This phonon “lasing” enhances the phonon occupation five orders of magnitude above the thermal value when tunable neighbor traps are red-shifted with respect to the pumped trap BEC emission at even harmonics of the vibration mode. These experiments, supported by a theoretical model, constitute the first demonstration of coherent cavity optomechanical phenomena with exciton polaritons, paving the way for new hybrid designs for quantum technologies, phonon lasers, and phonon-photon bidirectional translators. 1 Department of Physics, Centro Atómico Bariloche & Instituto Balseiro (CNEA) and CONICET, Universidad Nacional de Cuyo (UNCuyo), Av. E. Bustillo 9500, R8402AGP S.C. de Bariloche, Río Negro, Argentina. 2 Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., ✉ Hausvogteiplatz 5-7, 10117 Berlin, Germany. email: [email protected] NATURE COMMUNICATIONS | (2020) 11:4552 | https://doi.org/10.1038/s41467-020-18358-z | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-020-18358-z ybrid devices composed of different physical compo- observation highlights the relevance of high-order resonant Hnents with complementary functionalities constitute one optomechanical coupling in these devices. A theoretical model of trending line of research for novel quantum commu- resonant polariton-driven quadratic optomechanical coupling is nication technologies for signal storage, processing, conversion, introduced to describe the experimental observations. Conclu- and transmission1. Cavity optomechanics2 constitutes one sions are drawn showing that the findings contribute to devel- domain, in which hybrid designs have been envisaged both for oping new directions in the optomechanics and cavity-polariton the test of fundamental quantum physics at the mesoscopic fields, with applications in the technologically relevant extremely level, as well as for new functionalities3.Incavityopto- high-frequency range (30–300 GHz). mechanics photons are confined and strongly coupled to vibrational degrees of freedom, thus leading, under appropriate Results conditions, to dynamical back-action phenomena, including The polariton optomechanical device. The studied system con- optically induced coherent self-oscillation of the mechanical μ 4,5 sists of cavity polaritons in m-sized traps created by micro- mode and, conversely, to laser cooling of the mechanical 26 6–9 structuring the spacer of an (Al,Ga)As microcavity . The lateral mode,evendowntothequantumgroundstate . One appli- spacer modulation creates confinement potentials in 2D cation of cavity optomechanics is in the bidirectional conversion (wires and stripes), 3D (dots), as well as dot arrays consisting of between signals of contrastingly different frequency, for exam- non-etched areas surrounded by etched barriers (see a detailed ple, between classical microwaves and optical light10–12,with 13 description of the structure in the Supplementary Note 1). These prospects for the transfer of quantum states . Cavity polar- polariton traps were studied by low-temperature PL in ref. 26. The itons, the strongly coupled quantum states combining an exci- fi fi sample is in the strong coupling regime both in the etched and ton (as a two-level arti cial atom) and a cavity-con ned photon, non-etched regions, leading to microcavity polaritons in these are the fundamental excitations of another hybrid quantum 14 two regions with different energies and photon/exciton content. system . Since the initial discovery of cavity polaritons in BECs can be induced in the traps both with nonresonant and semiconductor microcavities, their Bose–Einstein condensation 24 15 fl 16 17 resonant excitation. As previously reported for similar planar (BEC) , super uidity ,lasing , also under electrical pump- 25 fi 18 19 and pillar microcavities, these structures also con ne breathing- ing , and multistable behavior have been reported. like longitudinal vibrations polarized along the growth direction, Hybrid quantum systems combining both cavity quantum z, with a fundamental frequency around ν0 20 GHz and electrodynamics and cavity optomechanics have been theoreti- m overtones at νn ¼ð1 þ 2nÞν0 . We will concentrate here on cally proposed20,21, with predictions of cooling at the single- m m experiments performed on a 40-μm-wide stripe (i.e., with weak polariton level, peculiar quantum statistics, and coupling to lateral confinement), as well as on a square array of coupled mechanical modes of both dispersive and dissipative nature. square traps of 1.6 μm lateral size separated by 3.2-μm-wide Cavity optomechanics with a polariton BEC opens intriguing etched regions. perspectives, particularly in view of the potential access to an optomechanical strong-coupling regime, and the possibility of using vibrations to actuate on such a macroscopic quantum fluid. Optomechanically induced amplification. Figure 1a, b shows the μ Indeed, the strength of the optomechanical interaction in spectrally and spatially resolved PL image of the 40- m-wide conventional photon cavity optomechanics is quantified by the polariton stripe recorded at 5 K. The photonic mode in this 4g2n ¼ 0 cav microstructure is slightly negatively detuned with respect to the optomechanical cooperativity, C κΓ . Here, g0 is the single- m QW heavy-hole exciton state. The PL was nonresonantly excited photon optomechanical coupling factor, ncav is the number of using a Ti-Sapphire cw laser (1.631 eV) with pump powers PPump photons in the cavity, and κ and Γ are the photon and m below, and above the condensation threshold power, PTh. At low mechanical decay rates, respectively2. For a polariton BEC one = −4 powers (Fig. 1a, PPump 10 PTh), the closely packed laterally expects strongly enhanced values of the cooperativity C due to the confined levels in the stripe can be identified. Above threshold = very large coherent population of the condensate, coherence (Fig. 1b, PPump 2.3 PTh), the polariton BEC is evidenced by the times that can be two orders of magnitude larger than the photon narrowing and concentration of the emission at the bottom of the lifetime in the cavity, and optomechanical coupling interactions trap, as well as by the blueshift of the states induced by mediated by the excitons that can be resonantly enhanced22. polariton–polariton interactions mediated by their excitonic Hybrid optomechanical systems based on BEC have, to the best of component, as well as polariton interactions with the excitonic our knowledge, so far only been demonstrated with cold atoms in reservoir17. cavities coupled to low-frequency kHz vibrational degrees of Figure 1c–f summarize the results of a two-laser OMIA freedom23. experiment27, performed on this 40-μm-wide stripe. The first It is the purpose of this paper to investigate the rich physics (pump) laser creates a BEC in the stripe. The second weak emerging from the coupling of a polariton BEC in a semi- (probe) laser was scanned from higher to lower energies and conductor microcavity with super-high-frequency vibrations through the condensate energy (details are provided in the confined in the same resonator24,25. The studied system contains Supplementary Note 2). The color map in Fig. 1c shows the PL GaAs/AlAs quantum wells (as two-level artificial atoms) coupled intensity as a function of the probe laser energy. Figure 1d to cavity-confined optical and vibrational modes. Planar semi- displays the integrated PL intensity, showing the emission of the conductor microcavities are microstructured to laterally confine closely spaced polariton states of the stripe. OMIA is evidenced the polaritons, and the phonons, in stripes and in trap arrays. by the variation of the PL intensity at the peak of the BEC Optomechanically induced amplification (OMIA) experiments emission as a function of the probe laser energy, which is also are presented to evidence the efficient coupling between the displayed in Fig. 1e. Notably, a series of peaks separated by the resulting exciton–polariton condensates to 20 GHz breathing-like energy of the fundamental breathing-like cavity-confined vibra- vibrations confined in the same cavity. High-resolution spatially tional mode (~20 GHz ~ 83 μeV) appears at the high-energy side resolved low-temperature photoluminescence (PL) experiments of the BEC peak. A fit of the OMIA peak detunings, showing a evidence the emergence of mechanical self-oscillation, when clear lineal dependence,
Load more

Recommended publications
  • Arxiv:2104.14459V2 [Cond-Mat.Mes-Hall] 13 Aug 2021 Rymksnnaeinayn Uha Bspromising Prop- Mbss This As Such Subsequent Anyons Commuting
    Majorana bound states in semiconducting nanostructures Katharina Laubscher1 and Jelena Klinovaja1 Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland (Dated: 16 August 2021) In this Tutorial, we give a pedagogical introduction to Majorana bound states (MBSs) arising in semiconduct- ing nanostructures. We start by briefly reviewing the well-known Kitaev chain toy model in order to introduce some of the basic properties of MBSs before proceeding to describe more experimentally relevant platforms. Here, our focus lies on simple ‘minimal’ models where the Majorana wave functions can be obtained explicitly by standard methods. In a first part, we review the paradigmatic model of a Rashba nanowire with strong spin-orbit interaction (SOI) placed in a magnetic field and proximitized by a conventional s-wave supercon- ductor. We identify the topological phase transition separating the trivial phase from the topological phase and demonstrate how the explicit Majorana wave functions can be obtained in the limit of strong SOI. In a second part, we discuss MBSs engineered from proximitized edge states of two-dimensional (2D) topological insulators. We introduce the Jackiw-Rebbi mechanism leading to the emergence of bound states at mass domain walls and show how this mechanism can be exploited to construct MBSs. Due to their recent interest, we also include a discussion of Majorana corner states in 2D second-order topological superconductors. This Tutorial is mainly aimed at graduate students—both theorists and experimentalists—seeking to familiarize themselves with some of the basic concepts in the field. I. INTRODUCTION In 1937, the Italian physicist Ettore Majorana pro- posed the existence of an exotic type of fermion—later termed a Majorana fermion—which is its own antiparti- cle.1 While the original idea of a Majorana fermion was brought forward in the context of high-energy physics,2 it later turned out that emergent excitations with re- FIG.
    [Show full text]
  • The New Era of Polariton Condensates David W
    The new era of polariton condensates David W. Snoke, and Jonathan Keeling Citation: Physics Today 70, 10, 54 (2017); doi: 10.1063/PT.3.3729 View online: https://doi.org/10.1063/PT.3.3729 View Table of Contents: http://physicstoday.scitation.org/toc/pto/70/10 Published by the American Institute of Physics Articles you may be interested in Ultraperipheral nuclear collisions Physics Today 70, 40 (2017); 10.1063/PT.3.3727 Death and succession among Finland’s nuclear waste experts Physics Today 70, 48 (2017); 10.1063/PT.3.3728 Taking the measure of water’s whirl Physics Today 70, 20 (2017); 10.1063/PT.3.3716 Microscopy without lenses Physics Today 70, 50 (2017); 10.1063/PT.3.3693 The relentless pursuit of hypersonic flight Physics Today 70, 30 (2017); 10.1063/PT.3.3762 Difficult decisions Physics Today 70, 8 (2017); 10.1063/PT.3.3706 David Snoke is a professor of physics and astronomy at the University of Pittsburgh in Pennsylvania. Jonathan Keeling is a reader in theoretical condensed-matter physics at the University of St Andrews in Scotland. The new era of POLARITON CONDENSATES David W. Snoke and Jonathan Keeling Quasiparticles of light and matter may be our best hope for harnessing the strange effects of quantum condensation and superfluidity in everyday applications. magine, if you will, a collection of many photons. Now and applied—remains to turn those ideas into practical technologies. But the dream imagine that they have mass, repulsive interactions, and isn’t as distant as it once seemed. number conservation.
    [Show full text]
  • Majorana Fermions in Quantum Wires and the Influence of Environment
    Freie Universitat¨ Berlin Department of Physics Master thesis Majorana fermions in quantum wires and the influence of environment Supervisor: Written by: Prof. Karsten Flensberg Konrad W¨olms Prof. Piet Brouwer 25. May 2012 Contents page 1 Introduction 5 2 Majorana Fermions 7 2.1 Kitaev model . .9 2.2 Helical Liquids . 12 2.3 Spatially varying Zeeman fields . 14 2.3.1 Scattering matrix criterion . 16 2.4 Application of the criterion . 17 3 Majorana qubits 21 3.1 Structure of the Majorana Qubits . 21 3.2 General Dephasing . 22 3.3 Majorana 4-point functions . 24 3.4 Topological protection . 27 4 Perturbative corrections 29 4.1 Local perturbations . 29 4.1.1 Calculation of the correlation function . 30 4.1.2 Non-adiabatic effects of noise . 32 4.1.3 Uniform movement of the Majorana fermion . 34 4.2 Coupling between Majorana fermions . 36 4.2.1 Static perturbation . 36 4.3 Phonon mediated coupling . 39 4.3.1 Split Majorana Green function . 39 4.3.2 Phonon Coupling . 40 4.3.3 Self-Energy . 41 4.3.4 Self Energy in terms of local functions . 43 4.4 Calculation of B ................................ 44 4.4.1 General form for the electron Green function . 46 4.5 Calculation of Σ . 46 5 Summary 51 6 Acknowledgments 53 Bibliography 55 3 1 Introduction One of the fascinating aspects of condensed matter is the emergence of quasi-particles. These often describe the low energy behavior of complicated many-body systems extremely well and have long become an essential tool for the theoretical description of many condensed matter system.
    [Show full text]
  • Tunable Phonon Polaritons in Atomically Thin Van Der Waals Crystals of Boron Nitride
    Tunable Phonon Polaritons in Atomically Thin van der Waals Crystals of Boron Nitride The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Dai, S., Z. Fei, Q. Ma, A. S. Rodin, M. Wagner, A. S. McLeod, M. K. Liu, et al. “Tunable Phonon Polaritons in Atomically Thin van Der Waals Crystals of Boron Nitride.” Science 343, no. 6175 (March 7, 2014): 1125–1129. As Published http://dx.doi.org/10.1126/science.1246833 Publisher American Association for the Advancement of Science (AAAS) Version Author's final manuscript Citable link http://hdl.handle.net/1721.1/90317 Terms of Use Creative Commons Attribution-Noncommercial-Share Alike Detailed Terms http://creativecommons.org/licenses/by-nc-sa/4.0/ Tunable phonon polaritons in atomically thin van der Waals crystals of boron nitride Authors: S. Dai1, Z. Fei1, Q. Ma2, A. S. Rodin3, M. Wagner1, A. S. McLeod1, M. K. Liu1, W. Gannett4,5, W. Regan4,5, K. Watanabe6, T. Taniguchi6, M. Thiemens7, G. Dominguez8, A. H. Castro Neto3,9, A. Zettl4,5, F. Keilmann10, P. Jarillo-Herrero2, M. M. Fogler1, D. N. Basov1* Affiliations: 1Department of Physics, University of California, San Diego, La Jolla, California 92093, USA 2Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 3Department of Physics, Boston University, Boston, Massachusetts 02215, USA 4Department of Physics and Astronomy, University of California, Berkeley, Berkeley, California 94720, USA 5Materials Sciences Division, Lawrence Berkeley
    [Show full text]
  • Chapter 10 Dynamic Condensation of Exciton-Polaritons
    Chapter 10 Dynamic condensation of exciton-polaritons 1 REVIEWS OF MODERN PHYSICS, VOLUME 82, APRIL–JUNE 2010 Exciton-polariton Bose-Einstein condensation Hui Deng Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA Hartmut Haug Institut für Theoretische Physik, Goethe Universität Frankfurt, Max-von-Laue-Street 1, D-60438 Frankfurt am Main, Germany Yoshihisa Yamamoto Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA; National Institute of Informatics, Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan; and NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa 243-0198, Japan ͑Published 12 May 2010͒ In the past decade, a two-dimensional matter-light system called the microcavity exciton-polariton has emerged as a new promising candidate of Bose-Einstein condensation ͑BEC͒ in solids. Many pieces of important evidence of polariton BEC have been established recently in GaAs and CdTe microcavities at the liquid helium temperature, opening a door to rich many-body physics inaccessible in experiments before. Technological progress also made polariton BEC at room temperatures promising. In parallel with experimental progresses, theoretical frameworks and numerical simulations are developed, and our understanding of the system has greatly advanced. In this article, recent experiments and corresponding theoretical pictures based on the Gross-Pitaevskii equations and the Boltzmann kinetic simulations for a finite-size BEC of polaritons are reviewed. DOI: 10.1103/RevModPhys.82.1489 PACS number͑s͒: 71.35.Lk, 71.36.ϩc, 42.50.Ϫp, 78.67.Ϫn CONTENTS A. Polariton-phonon scattering 1500 B. Polariton-polariton scattering 1500 1. Nonlinear polariton interaction coefficients 1500 I. Introduction 1490 2. Polariton-polariton scattering rates 1502 II.
    [Show full text]
  • Introducing Coherent Time Control to Cavity Magnon-Polariton Modes
    ARTICLE https://doi.org/10.1038/s42005-019-0266-x OPEN Introducing coherent time control to cavity magnon-polariton modes Tim Wolz 1*, Alexander Stehli1, Andre Schneider 1, Isabella Boventer1,2, Rair Macêdo 3, Alexey V. Ustinov1,4, Mathias Kläui 2 & Martin Weides 1,3* 1234567890():,; By connecting light to magnetism, cavity magnon-polaritons (CMPs) can link quantum computation to spintronics. Consequently, CMP-based information processing devices have emerged over the last years, but have almost exclusively been investigated with single-tone spectroscopy. However, universal computing applications will require a dynamic and on- demand control of the CMP within nanoseconds. Here, we perform fast manipulations of the different CMP modes with independent but coherent pulses to the cavity and magnon sys- tem. We change the state of the CMP from the energy exchanging beat mode to its normal modes and further demonstrate two fundamental examples of coherent manipulation. We first evidence dynamic control over the appearance of magnon-Rabi oscillations, i.e., energy exchange, and second, energy extraction by applying an anti-phase drive to the magnon. Our results show a promising approach to control building blocks valuable for a quantum internet and pave the way for future magnon-based quantum computing research. 1 Institute of Physics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany. 2 Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany. 3 James Watt School of Engineering, Electronics & Nanoscale Engineering
    [Show full text]
  • Binary Polariton Fluids
    Departement Fysica, Faculteit Wetenschappen, Universiteit Antwerpen Binary Polariton Fluids Auteur: Promotor: Mathias Van Regemortel Prof Dr. Michiel Wouters Proefschrift ter verkrijging van de graad van Master in de Fysica 2012-2013 i Abstract Polaritons are quasiparticles that rise from a strong coupling between photons and a dipole excitation in matter. When a quantum well is placed inside a planar microcavity, this strong coupling occurs between the incident light and the quantum well excitons, giving rise to a two-dimensional gas of polaritons. Thanks to their photonic component, these polaritons have a small effective mass, whereas the excitonic component mediates interactions. Since polaritons are unstable particles because the photons can escape from the microcavity, a constant injection of coherent photons is necessary to balance the losses. Therefore a polariton gas is inherently a non-equilibrium system, which involves a wide variety of interesting new physics. Since polaritons are excited coherently in the systems that are studied in this work, they form a coherent quantum fluid that can be regarded as a non-equilibrium Bose-Einstein condensate. In this work we will study polariton fluids that have two spin components. The main goal is to generalize and unify the already established theories for, on one side, single-spin polariton fluids, and on the other, two-spin Bose-Einstein condensates, which will also be the two fundamental theories on which we base this work. As such the generalized physics for describing a two-spin non-equilibrium quantum fluid will be examined in the view of these two, already profoundly studied systems. First of all we will generalize the concept of Bose-Einstein condensation for non-equilibrium systems and derive the appropriate wave equation, the non-equilibrium Gross-Pitaevskii equation, to start our work from.
    [Show full text]
  • Demonstration of a Polariton Step Potential by Local Variation of Light-Matter Coupling in a Van-Der-Waals Heterostructure
    Research Article Vol. 28, No. 13 / 22 June 2020 / Optics Express 18649 Demonstration of a polariton step potential by local variation of light-matter coupling in a van-der-Waals heterostructure C.RUPPRECHT,1 M.KLAAS,1 H.KNOPF,2,3,4 T. TANIGUCHI,4 K. WATANABE,4 Y. QIN,5,6 S.TONGAY,5,6 S.SCHRÖDER,3 F. EILENBERGER,2,3,4 S.HÖFLING,1 AND C.SCHNEIDER1,* 1Technische Physik and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems, Universität Würzburg, D-97074 Würzburg, Am Hubland, Germany 2Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University, Albert-Einstein-Straße 15, 07745 Jena, Germany 3Fraunhofer-Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Straße 7, 07745 Jena, Germany 4Max Planck School of Photonics, Albert-Einstein-Straße 7, 07745 Jena, Germany 5National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan 6Arizona State University, Tempe, AZ 85287, USA *[email protected] Abstract: The large oscillator strength of excitons in transition metal dichalcogenide layers facilitates the formation of exciton-polariton resonances for monolayers and van-der-Waals heterostructures embedded in optical microcavities. Here, we show, that locally changing the number of layers in a WSe2/hBN/WSe2 van-der-Waals heterostructure embedded in a monolithic, high-quality-factor cavity gives rise to a local variation of the coupling strength. This effect yields a polaritonic stair case potential, which we demonstrate at room temperature. Our result paves the way towards engineering local polaritonic potentials at length scales down to atomically sharp interfaces, based on purely modifying its real part contribution via the coherent light-matter coupling strength g.
    [Show full text]
  • Controlling Spins with Surface Magnon Polaritons Jamison Sloan
    Controlling spins with surface magnon polaritons by Jamison Sloan B.S. Physics Massachussetts Institute of Technology (2017) Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering and Computer Science at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2020 ○c Massachusetts Institute of Technology 2020. All rights reserved. Author............................................................. Department of Electrical Engineering and Computer Science May 13, 2020 Certified by . Marin Soljaciˇ c´ Professor of Physics Thesis Supervisor Accepted by. Leslie A. Kolodziejski Professor of Electrical Engineering and Computer Science Chair, Department Committee on Graduate Students 2 Controlling spins with surface magnon polaritons by Jamison Sloan Submitted to the Department of Electrical Engineering and Computer Science on May 13, 2020, in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering and Computer Science Abstract Polaritons in metals, semimetals, semiconductors, and polar insulators can allow for ex- treme confinement of electromagnetic energy, providing many promising opportunities for enhancing typically weak light-matter interactions such as multipolar radiation, multipho- ton spontaneous emission, Raman scattering, and material nonlinearities. These extremely confined polaritons are quasi-electrostatic in nature, with most of their energy residing in the electric field. As a result, these "electric" polaritons are far from optimized for en- hancing emission of a magnetic nature, such as spin relaxation, which is typically many orders of magnitude slower than corresponding electric decays. Here, we take concepts of “electric” polaritons into magnetic materials, and propose using surface magnon polaritons in negative magnetic permeability materials to strongly enhance spin-relaxation in nearby emitters.
    [Show full text]
  • Excitations of Quasi-Particles in Nanostructured Systems
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2017 Excitations of Quasi-Particles in Nanostructured Systems Jingxuan Ge University of Tennessee, Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Other Materials Science and Engineering Commons Recommended Citation Ge, Jingxuan, "Excitations of Quasi-Particles in Nanostructured Systems. " PhD diss., University of Tennessee, 2017. https://trace.tennessee.edu/utk_graddiss/4461 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Jingxuan Ge entitled "Excitations of Quasi- Particles in Nanostructured Systems." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Materials Science and Engineering. Gerd Duscher, Major Professor We have read this dissertation and recommend its acceptance: Ramki Kalyanaraman, Haixuan Xu, Dibyendu Mukherjee Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Excitations of Quasi-Particles in Nanostructured Systems A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Jingxuan Ge May 2017 Dedications To my father, my parents in-law, my husband, and my son.
    [Show full text]
  • Plasmons, Polarons, Polaritons
    Plasmons, polarons, polaritons • Dielectric function; EM wave in solids • Plasmon oscillation -- plasmons • Electrostatic screening • Electron-electron interaction • Mott metal-insulator transition • Electron-lattice interaction -- polarons • Photon-phonon interaction -- polaritons • Peierls instability of linear metals For mobile positive ions Dept of Phys M.C. Chang Dielectric function (r, t)-space (k,ω)-space ∇⋅Ert(,) =4πρ (,) rt ik⋅= E(, kωπρω ) 4 (, k ) ∇⋅Drt(,) =4πρ (,) rt ext ik⋅= D(, kω ) 4πρext (, k ω ) ()ρ = ρρext+ ind Take the Fourier “shuttle” between 2 spaces: dk3 dω E(,)rt= Ek (,ω ) eikr()⋅−ω t , same for D ∫ (2ππ )3 2 dk3 dω ρ(,)rt= ρω (, k ) eikr()⋅−ω t , same for ρ ∫ (2ππ )3 2 ext Dk( ,ωεω )= ( k , ) Ek ( , ω ) (by definition) or ρωεωρω(,kkk )= (, )(, ) (easier to calculate) ext or φωεωφωext (,kkkEkikk )==− (, )(, ) ∵ (, ω ) φω (, )... etc Q: What is the relation between D(r,t) and E(r,t)? EM wave propagation in metal Maxwell equations 1 ∂B iω ∇×ED= − ; ∇⋅ =4πρ ik×+ E= B ; ε k ⋅= E 4πρ ct∂ ext c ion ext 14∂D π iωπ4 ∇×BJB=; + + ∇⋅ =0ik×− B=;ε E + J ik ⋅= B 0 ct∂ c ext ccion ext JE= σ ωπω2 4 i ( ) →×kkE() ×= −22εσion E − E || cc 2 kkE()⋅− kE • Transverse wave 2 2 ωπσ⎛⎞4 i k =+2 ⎜⎟εion c ⎝⎠ω ω c ∵υ ==, refractive index n = ε p kn 4πσi (in the following, ∴εωε(,k )=ion + ω let εion ～1) • Longitudinal wave εω(,k )=0 Drude model of AC conductivity dv v meEtm=−() − eedt τ Assume −itω Et()= Ee0 then −itω vve= 0 emτ / →=−vEe ()t 1− iωτ →=−jnev =σω() E AC conductivity 2 σ 0 ne τ σω()=
    [Show full text]
  • Ultralow Threshold Polariton Condensate in a Monolayer
    Ultralow Threshold Polariton Condensate in a Monolayer Semiconductor Microcavity at Room Temperature Jiaxin Zhao1,#, Rui Su1,#, Antonio Fieramosca1, Weijie Zhao1, Wei Du1, Xue Liu1, Carole Diederichs 2,3, Daniele Sanvitto4, Timothy C. H. Liew1,2, Qihua Xiong1,2,5,* 1Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 2MajuLab, International Joint Research Unit UMI 3654, CNRS, Université Côte d’Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, Singapore 3Laboratoire Pierre Aigrain, Dé partement de physique de l’ENS, Ecole Normale Supé rieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité , Sorbonne Université s, UPMC Univ. Paris 06, CNRS, 75005 Paris, France 4CNR NANOTEC Institute of Nanotechnology, via Monteroni, 73100 Lecce, Italy 5State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China #These authors contributed equally to this work. *To whom correspondence should be addressed. Email: [email protected] 1 Abstract Atomically thin transition-metal dichalcogenides (TMDs) possess valley-dependent functionalities that are usually available only at crogenic temperatures, constrained by various valley depolarization scatterings. The formation of exciton polaritons (EPs) by coherently superimposing excitons and microcavity photons potentially harnesses the valley-polarized polariton-polariton interactions for novel valleytronics
    [Show full text]