Creating Extended Landau Levels of Large Degeneracy with Photons
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Magnetism, Free Electrons and Interactions
Magnetism Magnets Zero external field Finite external field • Types of magnetic systems • Pauli paramagnetism in metals Paramagnets • Landau diamagnetism in metals • Larmor diamagnetism in insulators Diamagnets • Ferromagnetism of electron gas • Spin Hamiltonian Ferromagnets • Mean field approach • Curie transition Antiferromagnets Ferrimagnets …… … Pauli paramagnetism Pauli paramagnetism Let us first look at magnetic properties of a free electron gas. ε =−p2 /2meBmc= /2 ε =+p2 /2meBmc= /2 ↑ ↓G Electron are spin-1/2 particles #of majority spins: dp3 NV= f()ε In external magnetic field B – Zeeman splitting #of minority spins: ↑,,↓ ∫ (2π= )3 ↑ ↓ 2 = 2 = ε↑ =−p /2meBmc /2 ε↓ =+p /2meBmc /2 Magnetization (magnetic moment per unit volume): - minority spins e= M =−()NN : aligned along the field and proportional Fermi level ↑ ↓ 2Vmc to B in low fields χ - magnetic succeptibility - majority spins M = χB χ > 0 - paramagnetism Pauli succeptibility Landau quantization G 2 2 A free electron in magnetic field: B & zˆ ε↑ =−p /2meBmc= /2 ε↓ =+p /2meBmc= /2 G 2 µ+eB= /2 mc 2 G VgeB= Schrödinger equation: = ⎛⎞ieA ABxAA===;0 NN−= gd()εε ≈ V −∇+=⎜⎟ψ εψ yxz ↑↓ ∫ 2mc= 22µ−eB= /2 mc mc ⎝⎠ B=1T corresponds toeBmc= /1=× K k provided m is free electrons’s mass Solutions: labeled by two indices nk, B G z For any fields, eBmc=/ µ ψ nk(r )= exp( ik y y+− ik z z )ϕ n ( x= ck y / eB ) Magnetic succeptibility: ϕn - wave functions of a harmonic oscillator 22 2 Energies: ε =+==kmeBmcn/2 ( / )( + 1/2) - strongly degenerate!! ⎛⎞e= nk z χP = ⎜⎟g ⎝⎠2mc We “quantized” momenta transverse to the field (Landau levels) 1 Landau diamagnetism Electrons in metals A free electron in magnetic field: moves along spiral trajectories We know that there are diamagnetic metals. -
Degenerate Eigenvalue Problem 32.1 Degenerate Perturbation
Physics 342 Lecture 32 Degenerate Eigenvalue Problem Lecture 32 Physics 342 Quantum Mechanics I Wednesday, April 23rd, 2008 We have the matrix form of the first order perturbative result from last time. This carries over pretty directly to the Schr¨odingerequation, with only minimal replacement (the inner product and finite vector space change, but notationally, the results are identical). Because there are a variety of quantum mechanical systems with degenerate spectra (like the Hydrogen 2 eigenstates, each En has n associated eigenstates) and we want to be able to predict the energy shift associated with perturbations in these systems, we can copy our arguments for matrices to cover matrices with more than one eigenvector per eigenvalue. The punch line of that program is that we can use the non-degenerate perturbed energies, provided we start with the \correct" degenerate linear combinations. 32.1 Degenerate Perturbation N×N Going back to our symmetric matrix example, we have A IR , and 2 again, a set of eigenvectors and eigenvalues: A xi = λi xi. This time, suppose that the eigenvalue λi has a set of M associated eigenvectors { that is, suppose a set of eigenvectors yj satisfy: A yj = λi yj j = 1 M (32.1) −! 1 of 9 32.1. DEGENERATE PERTURBATION Lecture 32 (so this represents M separate equations) that are themselves orthonormal1. Clearly, any linear combination of these vectors is also an eigenvector: M M X X A βk yk = λi βk yk: (32.2) k=1 k=1 M PM Define the general combination of yi to be z βk yk, also an f gi=1 ≡ k=1 eigenvector of A with eigenvalue λi. -
Rich Magnetic Quantization Phenomena in AA Bilayer Silicene
www.nature.com/scientificreports OPEN Rich Magnetic Quantization Phenomena in AA Bilayer Silicene Po-Hsin Shih1, Thi-Nga Do2,3, Godfrey Gumbs4,5, Danhong Huang6, Hai Duong Pham1 & Ming-Fa Lin1,7,8 Received: 13 June 2019 The rich magneto-electronic properties of AA-bottom-top (bt) bilayer silicene are investigated using Accepted: 27 August 2019 a generalized tight-binding model. The electronic structure exhibits two pairs of oscillatory energy Published: xx xx xxxx bands for which the lowest conduction and highest valence states of the low-lying pair are shifted away from the K point. The quantized Landau levels (LLs) are classifed into various separated groups by the localization behaviors of their spatial distributions. The LLs in the vicinity of the Fermi energy do not present simple wave function modes. This behavior is quite diferent from other two-dimensional systems. The geometry symmetry, intralayer and interlayer atomic interactions, and the efect of a perpendicular magnetic feld are responsible for the peculiar LL energy spectra in AA-bt bilayer silicene. This work provides a better understanding of the diverse magnetic quantization phenomena in 2D condensed-matter materials. Silicene, an isostructure to graphene, is purely made of silicon atoms through both the sp2 and sp3 bondings. So far, silicene systems have been successfully synthesized by the epitaxial growth on various substrate surfaces. Monolayer silicene with diferent sizes of unit cells has been produced on several substrates, such as Si(111) 1,2 3,4 5 6 33× -Ag template , Ag(111) (4 × 4) , Ir(111) ( 33× ) and ZrB2(0001) (2 × 2) . -
Topological Classification of Correlations in 2D Electron
materials Article Topological Classification of Correlations in 2D Electron Systems in Magnetic or Berry Fields Janusz E. Jacak Department of Quantum Technologies, Wrocław University of Science and Technology, Wyb. Wyspia´nskiego27, 50-370 Wrocław, Poland; [email protected] Abstract: Recent topology classification of 2D electron states induced by different homotopy classes of mappings of the planar Brillouin zone into Bloch space can be supplemented by a homotopy classification of various phases of multi-electron homotopy patterns induced by Coulomb interaction between electrons. The general classification of such type is presented. It explains the topologically protected correlations responsible for integer and fractional Hall effects in 2D multi-electron systems in the presence of perpendicular quantizing magnetic field or Berry field, the latter in topological Chern insulators. The long-range quantum entanglement is essential for homotopy correlated phases in contrast to local binary entanglement for conventional phases with local order parameters. The classification of homotopy long-range correlated phases induced by the Coulomb interaction of electrons has been derived in terms of homotopy invariants and illustrated by experimental observations in GaAs 2DES, graphene monolayer, and bilayer and in Chern topological insulators. The homotopy phases are demonstrated to be topologically protected and immune to the local crystal field, local disorder, and variation of the electron interaction strength. The nonzero interaction between electrons is shown, however, to be essential for the definition of the homotopy invariants, which disappear in gaseous systems. Citation: Jacak, J.E. Topological Keywords: homotopy phases; long-range quantum entanglement; FQHE; Hall systems; Chern Classification of Correlations in 2D topological insulators Electron Systems in Magnetic or Berry Field. -
UC Irvine UC Irvine Previously Published Works
UC Irvine UC Irvine Previously Published Works Title Astrophysics in 2006 Permalink https://escholarship.org/uc/item/5760h9v8 Journal Space Science Reviews, 132(1) ISSN 0038-6308 Authors Trimble, V Aschwanden, MJ Hansen, CJ Publication Date 2007-09-01 DOI 10.1007/s11214-007-9224-0 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Space Sci Rev (2007) 132: 1–182 DOI 10.1007/s11214-007-9224-0 Astrophysics in 2006 Virginia Trimble · Markus J. Aschwanden · Carl J. Hansen Received: 11 May 2007 / Accepted: 24 May 2007 / Published online: 23 October 2007 © Springer Science+Business Media B.V. 2007 Abstract The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the Universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Keywords Cosmology: general · Galaxies: general · ISM: general · Stars: general · Sun: general · Planets and satellites: general · Astrobiology · Star clusters · Binary stars · Clusters of galaxies · Gamma-ray bursts · Milky Way · Earth · Active galaxies · Supernovae 1 Introduction Astrophysics in 2006 modifies a long tradition by moving to a new journal, which you hold in your (real or virtual) hands. The fifteen previous articles in the series are referenced oc- casionally as Ap91 to Ap05 below and appeared in volumes 104–118 of Publications of V. -
25 Years of Quantum Hall Effect
S´eminaire Poincar´e2 (2004) 1 – 16 S´eminaire Poincar´e 25 Years of Quantum Hall Effect (QHE) A Personal View on the Discovery, Physics and Applications of this Quantum Effect Klaus von Klitzing Max-Planck-Institut f¨ur Festk¨orperforschung Heisenbergstr. 1 D-70569 Stuttgart Germany 1 Historical Aspects The birthday of the quantum Hall effect (QHE) can be fixed very accurately. It was the night of the 4th to the 5th of February 1980 at around 2 a.m. during an experiment at the High Magnetic Field Laboratory in Grenoble. The research topic included the characterization of the electronic transport of silicon field effect transistors. How can one improve the mobility of these devices? Which scattering processes (surface roughness, interface charges, impurities etc.) dominate the motion of the electrons in the very thin layer of only a few nanometers at the interface between silicon and silicon dioxide? For this research, Dr. Dorda (Siemens AG) and Dr. Pepper (Plessey Company) provided specially designed devices (Hall devices) as shown in Fig.1, which allow direct measurements of the resistivity tensor. Figure 1: Typical silicon MOSFET device used for measurements of the xx- and xy-components of the resistivity tensor. For a fixed source-drain current between the contacts S and D, the potential drops between the probes P − P and H − H are directly proportional to the resistivities ρxx and ρxy. A positive gate voltage increases the carrier density below the gate. For the experiments, low temperatures (typically 4.2 K) were used in order to suppress dis- turbing scattering processes originating from electron-phonon interactions. -
DEGENERACY CURVES, GAPS, and DIABOLICAL POINTS in the SPECTRA of NEUMANN PARALLELOGRAMS P Overfelt
DEGENERACY CURVES, GAPS, AND DIABOLICAL POINTS IN THE SPECTRA OF NEUMANN PARALLELOGRAMS P Overfelt To cite this version: P Overfelt. DEGENERACY CURVES, GAPS, AND DIABOLICAL POINTS IN THE SPECTRA OF NEUMANN PARALLELOGRAMS. 2020. hal-03017250 HAL Id: hal-03017250 https://hal.archives-ouvertes.fr/hal-03017250 Preprint submitted on 20 Nov 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. DEGENERACY CURVES, GAPS, AND DIABOLICAL POINTS IN THE SPECTRA OF NEUMANN PARALLELOGRAMS P. L. OVERFELT Abstract. In this paper we consider the problem of solving the Helmholtz equation over the space of all parallelograms subject to Neumann boundary conditions and determining the degeneracies occurring in their spectra upon changing the two parameters, angle and side ratio. This problem is solved numerically using the finite element method (FEM). Specifically for the lowest eleven normalized eigenvalue levels of the family of Neumann parallelograms, the intersection of two (or more) adjacent eigen- value level surfaces occurs in one of three ways: either as an isolated point associated with the special geometries, i.e., the rectangle, the square, or the rhombus, as part of a degeneracy curve which appears to contain an infinite number of points, or as a diabolical point in the Neumann parallelogram spec- trum. -
Path-Memory Induced Quantization of Classical Orbits SEE COMMENTARY
Path-memory induced quantization of classical orbits SEE COMMENTARY Emmanuel Forta,1, Antonin Eddib, Arezki Boudaoudc, Julien Moukhtarb, and Yves Couderb aInstitut Langevin, Ecole Supérieure de Physique et de Chimie Industrielles ParisTech and Université Paris Diderot, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7587, 10 Rue Vauquelin, 75 231 Paris Cedex 05, France; bMatières et Systèmes Complexes, Université Paris Diderot, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7057, Bâtiment Condorcet, 10 Rue Alice Domon et Léonie Duquet, 75013 Paris, France; and cLaboratoire de Physique Statistique, Ecole Normale Supérieure, 24 Rue Lhomond, 75231 Paris Cedex 05, France Edited* by Pierre C. Hohenberg, New York University, New York, NY, and approved August 4, 2010 (received for review May 26, 2010) A droplet bouncing on a liquid bath can self-propel due to its inter- a magnetic field. However, for technical reasons we chose a action with the waves it generates. The resulting “walker” is a variant that relies on the analogy first introduced by Berry et al. dynamical association where, at a macroscopic scale, a particle (5) between electromagnetic fields and surface waves. ~ ~ ~ (the droplet) is driven by a pilot-wave field. A specificity of this Its starting point is the similarity of relation B ¼ ∇ × A in elec- ~ system is that the wave field itself results from the superposition tromagnetism with 2Ω~¼ ∇~× U in fluid mechanics. In these re- ~ of the waves generated at the points of space recently visited by lations, the vorticity 2Ω~is the equivalent of the magnetic field B ~ ~ the particle. It thus contains a memory of the past trajectory of the and the velocity U that of the vector potential A. -
March 21–25, 2016
FORTY-SEVENTH LUNAR AND PLANETARY SCIENCE CONFERENCE PROGRAM OF TECHNICAL SESSIONS MARCH 21–25, 2016 The Woodlands Waterway Marriott Hotel and Convention Center The Woodlands, Texas INSTITUTIONAL SUPPORT Universities Space Research Association Lunar and Planetary Institute National Aeronautics and Space Administration CONFERENCE CO-CHAIRS Stephen Mackwell, Lunar and Planetary Institute Eileen Stansbery, NASA Johnson Space Center PROGRAM COMMITTEE CHAIRS David Draper, NASA Johnson Space Center Walter Kiefer, Lunar and Planetary Institute PROGRAM COMMITTEE P. Doug Archer, NASA Johnson Space Center Nicolas LeCorvec, Lunar and Planetary Institute Katherine Bermingham, University of Maryland Yo Matsubara, Smithsonian Institute Janice Bishop, SETI and NASA Ames Research Center Francis McCubbin, NASA Johnson Space Center Jeremy Boyce, University of California, Los Angeles Andrew Needham, Carnegie Institution of Washington Lisa Danielson, NASA Johnson Space Center Lan-Anh Nguyen, NASA Johnson Space Center Deepak Dhingra, University of Idaho Paul Niles, NASA Johnson Space Center Stephen Elardo, Carnegie Institution of Washington Dorothy Oehler, NASA Johnson Space Center Marc Fries, NASA Johnson Space Center D. Alex Patthoff, Jet Propulsion Laboratory Cyrena Goodrich, Lunar and Planetary Institute Elizabeth Rampe, Aerodyne Industries, Jacobs JETS at John Gruener, NASA Johnson Space Center NASA Johnson Space Center Justin Hagerty, U.S. Geological Survey Carol Raymond, Jet Propulsion Laboratory Lindsay Hays, Jet Propulsion Laboratory Paul Schenk, -
A Singular One-Dimensional Bound State Problem and Its Degeneracies
A Singular One-Dimensional Bound State Problem and its Degeneracies Fatih Erman1, Manuel Gadella2, Se¸cil Tunalı3, Haydar Uncu4 1 Department of Mathematics, Izmir˙ Institute of Technology, Urla, 35430, Izmir,˙ Turkey 2 Departamento de F´ısica Te´orica, At´omica y Optica´ and IMUVA. Universidad de Valladolid, Campus Miguel Delibes, Paseo Bel´en 7, 47011, Valladolid, Spain 3 Department of Mathematics, Istanbul˙ Bilgi University, Dolapdere Campus 34440 Beyo˘glu, Istanbul,˙ Turkey 4 Department of Physics, Adnan Menderes University, 09100, Aydın, Turkey E-mail: [email protected], [email protected], [email protected], [email protected] October 20, 2017 Abstract We give a brief exposition of the formulation of the bound state problem for the one-dimensional system of N attractive Dirac delta potentials, as an N N matrix eigenvalue problem (ΦA = ωA). The main aim of this paper is to illustrate that the non-degeneracy× theorem in one dimension breaks down for the equidistantly distributed Dirac delta potential, where the matrix Φ becomes a special form of the circulant matrix. We then give elementary proof that the ground state is always non-degenerate and the associated wave function may be chosen to be positive by using the Perron-Frobenius theorem. We also prove that removing a single center from the system of N delta centers shifts all the bound state energy levels upward as a simple consequence of the Cauchy interlacing theorem. Keywords. Point interactions, Dirac delta potentials, bound states. 1 Introduction Dirac delta potentials or point interactions, or sometimes called contact potentials are one of the exactly solvable classes of idealized potentials, and are used as a pedagogical tool to illustrate various physically important phenomena, where the de Broglie wavelength of the particle is much larger than the range of the interaction. -
Effect of Landau Quantization on the Equations of State in Dense Plasmas with Strong Magnetic Fields
High Power Laser Programme – Theory and Computation Effect of Landau quantization on the equations of state in dense plasmas with strong magnetic fields S Eliezera, P A Norreys, J T Mendonçab, K L Lancaster Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon., OX11 0QX, UK a on leave from Soreq NRC, Yavne 81800, Israel bon leave from Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal Main contact email address: [email protected] Introduction where Γ is phenomenological coefficient and TD is the Debye The equations of state (EOS) are the fundamental relation temperature. A very useful phenomenological EOS for a solid 2) between the macroscopically quantities describing a physical is given by the Gruneisen EOS , 1) system in equilibrium . The EOS relates all thermodynamic γ VE P = i quantities, such as density, pressure, energy, entropy, etc. i (3) Knowledge of the EOS is required in order to solve V 3 α V hydrodynamic equations in specific physical situations, such as γ = plasma physics associated with laser interaction with matter, κ c V shock wave physics, astrophysical objects etc. The properties of matter are summarised in the EOS. where the quantities on the right hand side of the second equation can be measured experimentally: α = linear expansion The concept of Landau quantization in the presence of strong coefficient, κ = isothermal compressibility, cV = specific heat at magnetic fields is presented in the rest of this section and, in the constant volume. There are more sophisticated EOS for next section, the electron EOS in the presence of strong ions3),4), however in this report we do not consider further the magnetic fields is calculated and presented for non-relativistic ion contributions. -
Digitalcommons@UTEP
University of Texas at El Paso DigitalCommons@UTEP Open Access Theses & Dissertations 2017-01-01 Her Alessandra Narvaez-Varela University of Texas at El Paso, [email protected] Follow this and additional works at: https://digitalcommons.utep.edu/open_etd Part of the Creative Writing Commons, and the Women's Studies Commons Recommended Citation Narvaez-Varela, Alessandra, "Her" (2017). Open Access Theses & Dissertations. 509. https://digitalcommons.utep.edu/open_etd/509 This is brought to you for free and open access by DigitalCommons@UTEP. It has been accepted for inclusion in Open Access Theses & Dissertations by an authorized administrator of DigitalCommons@UTEP. For more information, please contact [email protected]. HER ALESSANDRA NARVÁEZ-VARELA Master's Program in Creative Writing APPROVED: Sasha Pimentel, Chair Andrea Cote-Botero, Ph.D. David Ruiter, Ph.D. Charles Ambler, Ph.D. Dean of the Graduate School . Copyright © by Alessandra Narváez-Varela 2017 For my mother—Amanda Socorro Varela Aragón— the original Her HER by ALESSANDRA NARVÁEZ-VARELA, B.S in Biology, B.A. in Creative Writing THESIS Presented to the Faculty of the Graduate School of The University of Texas at El Paso in Partial Fulfillment of the Requirements for the Degree of MASTER OF FINE ARTS Department of Creative Writing THE UNIVERSITY OF TEXAS AT EL PASO December 2017 Acknowledgements Thank you to the editors of Duende for publishing a previous version of “The Cosmic Millimeter,” and to the Department of Hispanic Studies at the University of Houston for the forthcoming publication of a chapbook featuring the following poems: “Curves,” “Savage Nerd Cunt,” “Beauty,” “Bride,” “An Education,” “Daddy, Look at Me,” and “Cut.” Thank you to Casa Cultural de las Américas for sponsoring the reading that made this chapbook possible.