The Wave Function in Quantum Mechanics
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Computational Characterization of the Wave Propagation Behaviour of Multi-Stable Periodic Cellular Materials∗
Computational Characterization of the Wave Propagation Behaviour of Multi-Stable Periodic Cellular Materials∗ Camilo Valencia1, David Restrepo2,4, Nilesh D. Mankame3, Pablo D. Zavattieri 2y , and Juan Gomez 1z 1Civil Engineering Department, Universidad EAFIT, Medell´ın,050022, Colombia 2Lyles School of Civil Engineering, Purdue University, West Lafayette, IN 47907, USA 3Vehicle Systems Research Laboratory, General Motors Global Research & Development, Warren, MI 48092, USA. 4Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USA Abstract In this work, we present a computational analysis of the planar wave propagation behavior of a one-dimensional periodic multi-stable cellular material. Wave propagation in these ma- terials is interesting because they combine the ability of periodic cellular materials to exhibit stop and pass bands with the ability to dissipate energy through cell-level elastic instabilities. Here, we use Bloch periodic boundary conditions to compute the dispersion curves and in- troduce a new approach for computing wide band directionality plots. Also, we deconstruct the wave propagation behavior of this material to identify the contributions from its various structural elements by progressively building the unit cell, structural element by element, from a simple, homogeneous, isotropic primitive. Direct integration time domain analyses of a representative volume element at a few salient frequencies in the stop and pass bands are used to confirm the existence of partial band gaps in the response of the cellular material. Insights gained from the above analyses are then used to explore modifications of the unit cell that allow the user to tune the band gaps in the response of the material. -
Vector Wave Propagation Method Ein Beitrag Zum Elektromagnetischen Optikrechnen
Vector Wave Propagation Method Ein Beitrag zum elektromagnetischen Optikrechnen Inauguraldissertation zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften der Universitat¨ Mannheim vorgelegt von Dipl.-Inf. Matthias Wilhelm Fertig aus Mannheim Mannheim, 2011 Dekan: Prof. Dr.-Ing. Wolfgang Effelsberg Universitat¨ Mannheim Referent: Prof. Dr. rer. nat. Karl-Heinz Brenner Universitat¨ Heidelberg Korreferent: Prof. Dr.-Ing. Elmar Griese Universitat¨ Siegen Tag der mundlichen¨ Prufung:¨ 18. Marz¨ 2011 Abstract Based on the Rayleigh-Sommerfeld diffraction integral and the scalar Wave Propagation Method (WPM), the Vector Wave Propagation Method (VWPM) is introduced in the thesis. It provides a full vectorial and three-dimensional treatment of electromagnetic fields over the full range of spatial frequen- cies. A model for evanescent modes from [1] is utilized and eligible config- urations of the complex propagation vector are identified to calculate total internal reflection, evanescent coupling and to maintain the conservation law. The unidirectional VWPM is extended to bidirectional propagation of vectorial three-dimensional electromagnetic fields. Totally internal re- flected waves and evanescent waves are derived from complex Fresnel coefficients and the complex propagation vector. Due to the superposition of locally deformed plane waves, the runtime of the WPM is higher than the runtime of the BPM and therefore an efficient parallel algorithm is de- sirable. A parallel algorithm with a time-complexity that scales linear with the number of threads is presented. The parallel algorithm contains a mini- mum sequence of non-parallel code which possesses a time complexity of the one- or two-dimensional Fast Fourier Transformation. The VWPM and the multithreaded VWPM utilize the vectorial version of the Plane Wave Decomposition (PWD) in homogeneous medium without loss of accuracy to further increase the simulation speed. -
Superconducting Metamaterials for Waveguide Quantum Electrodynamics
ARTICLE DOI: 10.1038/s41467-018-06142-z OPEN Superconducting metamaterials for waveguide quantum electrodynamics Mohammad Mirhosseini1,2,3, Eunjong Kim1,2,3, Vinicius S. Ferreira1,2,3, Mahmoud Kalaee1,2,3, Alp Sipahigil 1,2,3, Andrew J. Keller1,2,3 & Oskar Painter1,2,3 Embedding tunable quantum emitters in a photonic bandgap structure enables control of dissipative and dispersive interactions between emitters and their photonic bath. Operation in 1234567890():,; the transmission band, outside the gap, allows for studying waveguide quantum electro- dynamics in the slow-light regime. Alternatively, tuning the emitter into the bandgap results in finite-range emitter–emitter interactions via bound photonic states. Here, we couple a transmon qubit to a superconducting metamaterial with a deep sub-wavelength lattice constant (λ/60). The metamaterial is formed by periodically loading a transmission line with compact, low-loss, low-disorder lumped-element microwave resonators. Tuning the qubit frequency in the vicinity of a band-edge with a group index of ng = 450, we observe an anomalous Lamb shift of −28 MHz accompanied by a 24-fold enhancement in the qubit lifetime. In addition, we demonstrate selective enhancement and inhibition of spontaneous emission of different transmon transitions, which provide simultaneous access to short-lived radiatively damped and long-lived metastable qubit states. 1 Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA 91125, USA. 2 Thomas J. Watson, Sr., Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA. 3 Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA 91125, USA. Correspondence and requests for materials should be addressed to O.P. -
Electromagnetism As Quantum Physics
Electromagnetism as Quantum Physics Charles T. Sebens California Institute of Technology May 29, 2019 arXiv v.3 The published version of this paper appears in Foundations of Physics, 49(4) (2019), 365-389. https://doi.org/10.1007/s10701-019-00253-3 Abstract One can interpret the Dirac equation either as giving the dynamics for a classical field or a quantum wave function. Here I examine whether Maxwell's equations, which are standardly interpreted as giving the dynamics for the classical electromagnetic field, can alternatively be interpreted as giving the dynamics for the photon's quantum wave function. I explain why this quantum interpretation would only be viable if the electromagnetic field were sufficiently weak, then motivate a particular approach to introducing a wave function for the photon (following Good, 1957). This wave function ultimately turns out to be unsatisfactory because the probabilities derived from it do not always transform properly under Lorentz transformations. The fact that such a quantum interpretation of Maxwell's equations is unsatisfactory suggests that the electromagnetic field is more fundamental than the photon. Contents 1 Introduction2 arXiv:1902.01930v3 [quant-ph] 29 May 2019 2 The Weber Vector5 3 The Electromagnetic Field of a Single Photon7 4 The Photon Wave Function 11 5 Lorentz Transformations 14 6 Conclusion 22 1 1 Introduction Electromagnetism was a theory ahead of its time. It held within it the seeds of special relativity. Einstein discovered the special theory of relativity by studying the laws of electromagnetism, laws which were already relativistic.1 There are hints that electromagnetism may also have held within it the seeds of quantum mechanics, though quantum mechanics was not discovered by cultivating those seeds. -
Matter Wave Speckle Observed in an Out-Of-Equilibrium Quantum Fluid
Matter wave speckle observed in an out-of-equilibrium quantum fluid Pedro E. S. Tavaresa, Amilson R. Fritscha, Gustavo D. Tellesa, Mahir S. Husseinb, Franc¸ois Impensc, Robin Kaiserd, and Vanderlei S. Bagnatoa,1 aInstituto de F´ısica de Sao˜ Carlos, Universidade de Sao˜ Paulo, 13560-970 Sao˜ Carlos, SP, Brazil; bDepartamento de F´ısica, Instituto Tecnologico´ de Aeronautica,´ 12.228-900 Sao˜ Jose´ dos Campos, SP, Brazil; cInstituto de F´ısica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ, Brazil; and dUniversite´ Nice Sophia Antipolis, Institut Non-Lineaire´ de Nice, CNRS UMR 7335, F-06560 Valbonne, France Contributed by Vanderlei Bagnato, October 16, 2017 (sent for review August 14, 2017; reviewed by Alexander Fetter, Nikolaos P. Proukakis, and Marlan O. Scully) We report the results of the direct comparison of a freely expanding turbulent Bose–Einstein condensate and a propagating optical speckle pattern. We found remarkably similar statistical properties underlying the spatial propagation of both phenomena. The cal- culated second-order correlation together with the typical correlation length of each system is used to compare and substantiate our observations. We believe that the close analogy existing between an expanding turbulent quantum gas and a traveling optical speckle might burgeon into an exciting research field investigating disordered quantum matter. matter–wave j speckle j quantum gas j turbulence oherent matter–wave systems such as a Bose–Einstein condensate (BEC) or atom lasers and atom optics are reality and relevant Cresearch fields. The spatial propagation of coherent matter waves has been an interesting topic for many theoretical (1–3) and experimental studies (4–7). -
Analysis of Nonlinear Dynamics in a Classical Transmon Circuit
Analysis of Nonlinear Dynamics in a Classical Transmon Circuit Sasu Tuohino B. Sc. Thesis Department of Physical Sciences Theoretical Physics University of Oulu 2017 Contents 1 Introduction2 2 Classical network theory4 2.1 From electromagnetic fields to circuit elements.........4 2.2 Generalized flux and charge....................6 2.3 Node variables as degrees of freedom...............7 3 Hamiltonians for electric circuits8 3.1 LC Circuit and DC voltage source................8 3.2 Cooper-Pair Box.......................... 10 3.2.1 Josephson junction.................... 10 3.2.2 Dynamics of the Cooper-pair box............. 11 3.3 Transmon qubit.......................... 12 3.3.1 Cavity resonator...................... 12 3.3.2 Shunt capacitance CB .................. 12 3.3.3 Transmon Lagrangian................... 13 3.3.4 Matrix notation in the Legendre transformation..... 14 3.3.5 Hamiltonian of transmon................. 15 4 Classical dynamics of transmon qubit 16 4.1 Equations of motion for transmon................ 16 4.1.1 Relations with voltages.................. 17 4.1.2 Shunt resistances..................... 17 4.1.3 Linearized Josephson inductance............. 18 4.1.4 Relation with currents................... 18 4.2 Control and read-out signals................... 18 4.2.1 Transmission line model.................. 18 4.2.2 Equations of motion for coupled transmission line.... 20 4.3 Quantum notation......................... 22 5 Numerical solutions for equations of motion 23 5.1 Design parameters of the transmon................ 23 5.2 Resonance shift at nonlinear regime............... 24 6 Conclusions 27 1 Abstract The focus of this thesis is on classical dynamics of a transmon qubit. First we introduce the basic concepts of the classical circuit analysis and use this knowledge to derive the Lagrangians and Hamiltonians of an LC circuit, a Cooper-pair box, and ultimately we derive Hamiltonian for a transmon qubit. -
A Photomechanics Study of Wave Propagation John Barclay Ligon Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1971 A photomechanics study of wave propagation John Barclay Ligon Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Applied Mechanics Commons Recommended Citation Ligon, John Barclay, "A photomechanics study of wave propagation " (1971). Retrospective Theses and Dissertations. 4556. https://lib.dr.iastate.edu/rtd/4556 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. 72-12,567 LIGON, John Barclay, 1940- A PHOTOMECHANICS STUDY OF WAVE PROPAGATION. Iowa State University, Ph.D., 1971 Engineering Mechanics University Microfilms. A XEROX Company, Ann Arbor. Michigan THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED A photomechanics study of wave propagation John Barclay Ligon A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject; Engineering Mechanics Approved Signature was redacted for privacy. Signature was redacted for privacy. Signature was redacted for privacy. For the Graduate College Iowa State University Ames, Iowa 1971 PLEASE NOTE; Some pages have indistinct print. -
Path Integrals in Quantum Mechanics
Path Integrals in Quantum Mechanics Emma Wikberg Project work, 4p Department of Physics Stockholm University 23rd March 2006 Abstract The method of Path Integrals (PI’s) was developed by Richard Feynman in the 1940’s. It offers an alternate way to look at quantum mechanics (QM), which is equivalent to the Schrödinger formulation. As will be seen in this project work, many "elementary" problems are much more difficult to solve using path integrals than ordinary quantum mechanics. The benefits of path integrals tend to appear more clearly while using quantum field theory (QFT) and perturbation theory. However, one big advantage of Feynman’s formulation is a more intuitive way to interpret the basic equations than in ordinary quantum mechanics. Here we give a basic introduction to the path integral formulation, start- ing from the well known quantum mechanics as formulated by Schrödinger. We show that the two formulations are equivalent and discuss the quantum mechanical interpretations of the theory, as well as the classical limit. We also perform some explicit calculations by solving the free particle and the harmonic oscillator problems using path integrals. The energy eigenvalues of the harmonic oscillator is found by exploiting the connection between path integrals, statistical mechanics and imaginary time. Contents 1 Introduction and Outline 2 1.1 Introduction . 2 1.2 Outline . 2 2 Path Integrals from ordinary Quantum Mechanics 4 2.1 The Schrödinger equation and time evolution . 4 2.2 The propagator . 6 3 Equivalence to the Schrödinger Equation 8 3.1 From the Schrödinger equation to PI’s . 8 3.2 From PI’s to the Schrödinger equation . -
1 the Principle of Wave–Particle Duality: an Overview
3 1 The Principle of Wave–Particle Duality: An Overview 1.1 Introduction In the year 1900, physics entered a period of deep crisis as a number of peculiar phenomena, for which no classical explanation was possible, began to appear one after the other, starting with the famous problem of blackbody radiation. By 1923, when the “dust had settled,” it became apparent that these peculiarities had a common explanation. They revealed a novel fundamental principle of nature that wascompletelyatoddswiththeframeworkofclassicalphysics:thecelebrated principle of wave–particle duality, which can be phrased as follows. The principle of wave–particle duality: All physical entities have a dual character; they are waves and particles at the same time. Everything we used to regard as being exclusively a wave has, at the same time, a corpuscular character, while everything we thought of as strictly a particle behaves also as a wave. The relations between these two classically irreconcilable points of view—particle versus wave—are , h, E = hf p = (1.1) or, equivalently, E h f = ,= . (1.2) h p In expressions (1.1) we start off with what we traditionally considered to be solely a wave—an electromagnetic (EM) wave, for example—and we associate its wave characteristics f and (frequency and wavelength) with the corpuscular charac- teristics E and p (energy and momentum) of the corresponding particle. Conversely, in expressions (1.2), we begin with what we once regarded as purely a particle—say, an electron—and we associate its corpuscular characteristics E and p with the wave characteristics f and of the corresponding wave. -
Relativistic Quantum Mechanics 1
Relativistic Quantum Mechanics 1 The aim of this chapter is to introduce a relativistic formalism which can be used to describe particles and their interactions. The emphasis 1.1 SpecialRelativity 1 is given to those elements of the formalism which can be carried on 1.2 One-particle states 7 to Relativistic Quantum Fields (RQF), which underpins the theoretical 1.3 The Klein–Gordon equation 9 framework of high energy particle physics. We begin with a brief summary of special relativity, concentrating on 1.4 The Diracequation 14 4-vectors and spinors. One-particle states and their Lorentz transforma- 1.5 Gaugesymmetry 30 tions follow, leading to the Klein–Gordon and the Dirac equations for Chaptersummary 36 probability amplitudes; i.e. Relativistic Quantum Mechanics (RQM). Readers who want to get to RQM quickly, without studying its foun- dation in special relativity can skip the first sections and start reading from the section 1.3. Intrinsic problems of RQM are discussed and a region of applicability of RQM is defined. Free particle wave functions are constructed and particle interactions are described using their probability currents. A gauge symmetry is introduced to derive a particle interaction with a classical gauge field. 1.1 Special Relativity Einstein’s special relativity is a necessary and fundamental part of any Albert Einstein 1879 - 1955 formalism of particle physics. We begin with its brief summary. For a full account, refer to specialized books, for example (1) or (2). The- ory oriented students with good mathematical background might want to consult books on groups and their representations, for example (3), followed by introductory books on RQM/RQF, for example (4). -
Realism About the Wave Function
Realism about the Wave Function Eddy Keming Chen* Forthcoming in Philosophy Compass Penultimate version of June 12, 2019 Abstract A century after the discovery of quantum mechanics, the meaning of quan- tum mechanics still remains elusive. This is largely due to the puzzling nature of the wave function, the central object in quantum mechanics. If we are real- ists about quantum mechanics, how should we understand the wave function? What does it represent? What is its physical meaning? Answering these ques- tions would improve our understanding of what it means to be a realist about quantum mechanics. In this survey article, I review and compare several realist interpretations of the wave function. They fall into three categories: ontological interpretations, nomological interpretations, and the sui generis interpretation. For simplicity, I will focus on non-relativistic quantum mechanics. Keywords: quantum mechanics, wave function, quantum state of the universe, sci- entific realism, measurement problem, configuration space realism, Hilbert space realism, multi-field, spacetime state realism, laws of nature Contents 1 Introduction 2 2 Background 3 2.1 The Wave Function . .3 2.2 The Quantum Measurement Problem . .6 3 Ontological Interpretations 8 3.1 A Field on a High-Dimensional Space . .8 3.2 A Multi-field on Physical Space . 10 3.3 Properties of Physical Systems . 11 3.4 A Vector in Hilbert Space . 12 *Department of Philosophy MC 0119, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0119. Website: www.eddykemingchen.net. Email: [email protected] 1 4 Nomological Interpretations 13 4.1 Strong Nomological Interpretations . 13 4.2 Weak Nomological Interpretations . -
Quantum Mechanics in 1-D Potentials
MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Electrical Engineering and Computer Science 6.007 { Electromagnetic Energy: From Motors to Lasers Spring 2011 Tutorial 10: Quantum Mechanics in 1-D Potentials Quantum mechanical model of the universe, allows us describe atomic scale behavior with great accuracy|but in a way much divorced from our perception of everyday reality. Are photons, electrons, atoms best described as particles or waves? Simultaneous wave-particle description might be the most accurate interpretation, which leads us to develop a mathe- matical abstraction. 1 Rules for 1-D Quantum Mechanics Our mathematical abstraction of choice is the wave function, sometimes denoted as , and it allows us to predict the statistical outcomes of experiments (i.e., the outcomes of our measurements) according to a few rules 1. At any given time, the state of a physical system is represented by a wave function (x), which|for our purposes|is a complex, scalar function dependent on position. The quantity ρ (x) = ∗ (x) (x) is a probability density function. Furthermore, is complete, and tells us everything there is to know about the particle. 2. Every measurable attribute of a physical system is represented by an operator that acts on the wave function. In 6.007, we're largely interested in position (x^) and momentum (p^) which have operator representations in the x-dimension @ x^ ! x p^ ! ~ : (1) i @x Outcomes of measurements are described by the expectation values of the operator Z Z @ hx^i = dx ∗x hp^i = dx ∗ ~ : (2) i @x In general, any dynamical variable Q can be expressed as a function of x and p, and we can find the expectation value of Z h @ hQ (x; p)i = dx ∗Q x; : (3) i @x 3.