SPS Chapter Research Award Proposal
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Schrödinger Equation)
Lecture 37 (Schrödinger Equation) Physics 2310-01 Spring 2020 Douglas Fields Reduced Mass • OK, so the Bohr model of the atom gives energy levels: • But, this has one problem – it was developed assuming the acceleration of the electron was given as an object revolving around a fixed point. • In fact, the proton is also free to move. • The acceleration of the electron must then take this into account. • Since we know from Newton’s third law that: • If we want to relate the real acceleration of the electron to the force on the electron, we have to take into account the motion of the proton too. Reduced Mass • So, the relative acceleration of the electron to the proton is just: • Then, the force relation becomes: • And the energy levels become: Reduced Mass • The reduced mass is close to the electron mass, but the 0.0054% difference is measurable in hydrogen and important in the energy levels of muonium (a hydrogen atom with a muon instead of an electron) since the muon mass is 200 times heavier than the electron. • Or, in general: Hydrogen-like atoms • For single electron atoms with more than one proton in the nucleus, we can use the Bohr energy levels with a minor change: e4 → Z2e4. • For instance, for He+ , Uncertainty Revisited • Let’s go back to the wave function for a travelling plane wave: • Notice that we derived an uncertainty relationship between k and x that ended being an uncertainty relation between p and x (since p=ћk): Uncertainty Revisited • Well it turns out that the same relation holds for ω and t, and therefore for E and t: • We see this playing an important role in the lifetime of excited states. -
The Theory of (Exclusively) Local Beables
The Theory of (Exclusively) Local Beables Travis Norsen Marlboro College Marlboro, VT 05344 (Dated: June 17, 2010) Abstract It is shown how, starting with the de Broglie - Bohm pilot-wave theory, one can construct a new theory of the sort envisioned by several of QM’s founders: a Theory of Exclusively Local Beables (TELB). In particular, the usual quantum mechanical wave function (a function on a high-dimensional configuration space) is not among the beables posited by the new theory. Instead, each particle has an associated “pilot- wave” field (living in physical space). A number of additional fields (also fields on physical space) maintain what is described, in ordinary quantum theory, as “entanglement.” The theory allows some interesting new perspective on the kind of causation involved in pilot-wave theories in general. And it provides also a concrete example of an empirically viable quantum theory in whose formulation the wave function (on configuration space) does not appear – i.e., it is a theory according to which nothing corresponding to the configuration space wave function need actually exist. That is the theory’s raison d’etre and perhaps its only virtue. Its vices include the fact that it only reproduces the empirical predictions of the ordinary pilot-wave theory (equivalent, of course, to the predictions of ordinary quantum theory) for spinless non-relativistic particles, and only then for wave functions that are everywhere analytic. The goal is thus not to recommend the TELB proposed here as a replacement for ordinary pilot-wave theory (or ordinary quantum theory), but is rather to illustrate (with a crude first stab) that it might be possible to construct a plausible, empirically arXiv:0909.4553v3 [quant-ph] 17 Jun 2010 viable TELB, and to recommend this as an interesting and perhaps-fruitful program for future research. -
On the Foundations of Eurhythmic Physics: a Brief Non Technical Survey
International Journal of Philosophy 2017; 5(6): 50-53 http://www.sciencepublishinggroup.com/j/ijp doi: 10.11648/j.ijp.20170506.11 ISSN: 2330-7439 (Print); ISSN: 2330-7455 (Online) On the Foundations of Eurhythmic Physics: A Brief Non Technical Survey Paulo Castro 1, José Ramalho Croca 1, 2, Rui Moreira 1, Mário Gatta 1, 3 1Center for Philosophy of Sciences of the University of Lisbon (CFCUL), Lisbon, Portugal 2Department of Physics, University of Lisbon, Lisbon, Portugal 3Centro de Investigação Naval (CINAV), Portuguese Naval Academy, Almada, Portugal Email address: To cite this article: Paulo Castro, José Ramalho Croca, Rui Moreira, Mário Gatta. On the Foundations of Eurhythmic Physics: A Brief Non Technical Survey. International Journal of Philosophy . Vol. 5, No. 6, 2017, pp. 50-53. doi: 10.11648/j.ijp.20170506.11 Received : October 9, 2017; Accepted : November 13, 2017; Published : February 3, 2018 Abstract: Eurhythmic Physics is a new approach to describe physical systems, where the concepts of rhythm, synchronization, inter-relational influence and non-linear emergence stand out as major concepts. The theory, still under development, is based on the Principle of Eurhythmy, the assertion that all systems follow, on average, the behaviors that extend their existence, preserving and reinforcing their structural stability. The Principle of Eurhythmy implies that all systems in Nature tend to harmonize or cooperate between themselves in order to persist, giving rise to more complex structures. This paper provides a brief non-technical introduction to the subject. Keywords: Eurhythmic Physics, Principle of Eurhythmy, Non-Linearity, Emergence, Complex Systems, Cooperative Evolution among a wider range of interactions. -
The Statistical Interpretation of Entangled States B
The Statistical Interpretation of Entangled States B. C. Sanctuary Department of Chemistry, McGill University 801 Sherbrooke Street W Montreal, PQ, H3A 2K6, Canada Abstract Entangled EPR spin pairs can be treated using the statistical ensemble interpretation of quantum mechanics. As such the singlet state results from an ensemble of spin pairs each with an arbitrary axis of quantization. This axis acts as a quantum mechanical hidden variable. If the spins lose coherence they disentangle into a mixed state. Whether or not the EPR spin pairs retain entanglement or disentangle, however, the statistical ensemble interpretation resolves the EPR paradox and gives a mechanism for quantum “teleportation” without the need for instantaneous action-at-a-distance. Keywords: Statistical ensemble, entanglement, disentanglement, quantum correlations, EPR paradox, Bell’s inequalities, quantum non-locality and locality, coincidence detection 1. Introduction The fundamental questions of quantum mechanics (QM) are rooted in the philosophical interpretation of the wave function1. At the time these were first debated, covering the fifty or so years following the formulation of QM, the arguments were based primarily on gedanken experiments2. Today the situation has changed with numerous experiments now possible that can guide us in our search for the true nature of the microscopic world, and how The Infamous Boundary3 to the macroscopic world is breached. The current view is based upon pivotal experiments, performed by Aspect4 showing that quantum mechanics is correct and Bell’s inequalities5 are violated. From this the non-local nature of QM became firmly entrenched in physics leading to other experiments, notably those demonstrating that non-locally is fundamental to quantum “teleportation”. -
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. -
Uniting the Wave and the Particle in Quantum Mechanics
Uniting the wave and the particle in quantum mechanics Peter Holland1 (final version published in Quantum Stud.: Math. Found., 5th October 2019) Abstract We present a unified field theory of wave and particle in quantum mechanics. This emerges from an investigation of three weaknesses in the de Broglie-Bohm theory: its reliance on the quantum probability formula to justify the particle guidance equation; its insouciance regarding the absence of reciprocal action of the particle on the guiding wavefunction; and its lack of a unified model to represent its inseparable components. Following the author’s previous work, these problems are examined within an analytical framework by requiring that the wave-particle composite exhibits no observable differences with a quantum system. This scheme is implemented by appealing to symmetries (global gauge and spacetime translations) and imposing equality of the corresponding conserved Noether densities (matter, energy and momentum) with their Schrödinger counterparts. In conjunction with the condition of time reversal covariance this implies the de Broglie-Bohm law for the particle where the quantum potential mediates the wave-particle interaction (we also show how the time reversal assumption may be replaced by a statistical condition). The method clarifies the nature of the composite’s mass, and its energy and momentum conservation laws. Our principal result is the unification of the Schrödinger equation and the de Broglie-Bohm law in a single inhomogeneous equation whose solution amalgamates the wavefunction and a singular soliton model of the particle in a unified spacetime field. The wavefunction suffers no reaction from the particle since it is the homogeneous part of the unified field to whose source the particle contributes via the quantum potential. -
Pilot-Wave Hydrodynamics
FL47CH12-Bush ARI 1 December 2014 20:26 Pilot-Wave Hydrodynamics John W.M. Bush Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; email: [email protected] Annu. Rev. Fluid Mech. 2015. 47:269–92 Keywords First published online as a Review in Advance on walking drops, Faraday waves, quantum analogs September 10, 2014 The Annual Review of Fluid Mechanics is online at Abstract fluid.annualreviews.org Yves Couder, Emmanuel Fort, and coworkers recently discovered that a This article’s doi: millimetric droplet sustained on the surface of a vibrating fluid bath may 10.1146/annurev-fluid-010814-014506 self-propel through a resonant interaction with its own wave field. This ar- Copyright c 2015 by Annual Reviews. ticle reviews experimental evidence indicating that the walking droplets ex- All rights reserved hibit certain features previously thought to be exclusive to the microscopic, Annu. Rev. Fluid Mech. 2015.47:269-292. Downloaded from www.annualreviews.org quantum realm. It then reviews theoretical descriptions of this hydrody- namic pilot-wave system that yield insight into the origins of its quantum- Access provided by Massachusetts Institute of Technology (MIT) on 01/07/15. For personal use only. like behavior. Quantization arises from the dynamic constraint imposed on the droplet by its pilot-wave field, and multimodal statistics appear to be a feature of chaotic pilot-wave dynamics. I attempt to assess the po- tential and limitations of this hydrodynamic system as a quantum analog. This fluid system is compared to quantum pilot-wave theories, shown to be markedly different from Bohmian mechanics and more closely related to de Broglie’s original conception of quantum dynamics, his double-solution theory, and its relatively recent extensions through researchers in stochastic electrodynamics. -
Pilot-Wave Theory, Bohmian Metaphysics, and the Foundations of Quantum Mechanics Lecture 8 Bohmian Metaphysics: the Implicate Order and Other Arcana
Pilot-wave theory, Bohmian metaphysics, and the foundations of quantum mechanics Lecture 8 Bohmian metaphysics: the implicate order and other arcana Mike Towler TCM Group, Cavendish Laboratory, University of Cambridge www.tcm.phy.cam.ac.uk/∼mdt26 and www.vallico.net/tti/tti.html [email protected] – Typeset by FoilTEX – 1 Acknowledgements The material in this lecture is largely derived from books and articles by David Bohm, Basil Hiley, Paavo Pylkk¨annen, F. David Peat, Marcello Guarini, Jack Sarfatti, Lee Nichol, Andrew Whitaker, and Constantine Pagonis. The text of an interview between Simeon Alev and Peat is extensively quoted. Other sources used and many other interesting papers are listed on the course web page: www.tcm.phy.cam.ac.uk/∼mdt26/pilot waves.html MDT – Typeset by FoilTEX – 2 More philosophical preliminaries Positivism: Observed phenomena are all that require discussion or scientific analysis; consideration of other questions, such as what the underlying mechanism may be, or what ‘real entities’ produce the phenomena, is dismissed as meaningless. Truth begins in sense experience, but does not end there. Positivism fails to prove that there are not abstract ideas, laws, and principles, beyond particular observable facts and relationships and necessary principles, or that we cannot know them. Nor does it prove that material and corporeal things constitute the whole order of existing beings, and that our knowledge is limited to them. Positivism ignores all humanly significant and interesting problems, citing its refusal to engage in reflection; it gives to a particular methodology an absolutist status and can do this only because it has partly forgotten, partly repressed its knowledge of the roots of this methodology in human concerns. -
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Hamiltonian Formulation of the Pilot-Wave Theory Has Also Been Developed by Holland [9]
Hamiltonian Formulation of the Pilot-Wave Theory Dan N. Vollick Irving K. Barber School of Arts and Sciences University of British Columbia Okanagan 3333 University Way Kelowna, B.C. Canada V1V 1V7 Abstract In the pilot-wave theory of quantum mechanics particles have definite positions and velocities and the system evolves deterministically. The velocity of a particle is deter- mined by the wave function of the system (the guidance equation) and the wave function evolves according to Schrodinger’s equation. In this paper I first construct a Hamiltonian that gives Schrodinger’s equation and the guidance equation for the particle. I then find the Hamiltonian for a relativistic particle in Dirac’s theory and for a quantum scalar field. arXiv:2101.10117v1 [quant-ph] 21 Jan 2021 1 1 Introduction In the standard approach to quantum mechanics the wave function provides a complete description of any system and is used to calculate probability distributions for observ- ables associated with the system. In the pilot-wave theory pioneered by de Broglie [1, 2] in the 1920’s, particles have definite positions and velocities and are “guided” by the wave function, which satisfies Schrodinger’s equation. A similar approach was developed by Bohm [3, 4] in the early 1950’s (see [5] and [6] for extensive reviews). For a single particle in the non-relativistic theory the velocity of the particle is given by dX~ = J~(X,~ t) , (1) dt where X~ is the particle’s position and h¯ J~ = ψ∗ ~ ψ ψ ~ ψ∗ . (2) 2im ψ 2 ∇ − ∇ | | h i Particle trajectories are, therefore, integral curves to the vector field J~. -
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. -
SIMULATED INTERPRETATION of QUANTUM MECHANICS Miroslav Súkeník & Jozef Šima
SIMULATED INTERPRETATION OF QUANTUM MECHANICS Miroslav Súkeník & Jozef Šima Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovakia Abstract: The paper deals with simulated interpretation of quantum mechanics. This interpretation is based on possibilities of computer simulation of our Universe. 1: INTRODUCTION Quantum theory and theory of relativity are two fundamental theories elaborated in the 20th century. In spite of the stunning precision of many predictions of quantum mechanics, its interpretation remains still unclear. This ambiguity has not only serious physical but mainly philosophical consequences. The commonest interpretations include the Copenhagen probability interpretation [1], many-words interpretation [2], and de Broglie-Bohm interpretation (theory of pilot wave) [3]. The last mentioned theory takes place in a single space-time, is non - local, and is deterministic. Moreover, Born’s ensemble and Watanabe’s time-symmetric theory being an analogy of Wheeler – Feynman theory should be mentioned. The time-symmetric interpretation was later, in the 60s re- elaborated by Aharonov and it became in the 80s the starting point for so called transactional interpretation of quantum mechanics. More modern interpretations cover a spontaneous collapse of wave function (here, a new non-linear component, causing this collapse is added to Schrödinger equation), decoherence interpretation (wave function is reduced due to an interaction of a quantum- mechanical system with its surroundings) and relational interpretation [4] elaborated by C. Rovelli in 1996. This interpretation treats the state of a quantum system as being observer-dependent, i.e. the state is the relation between the observer and the system. Relational interpretation is able to solve the EPR paradox. -
Path Integral Quantum Monte Carlo Study of Coupling and Proximity Effects in Superfluid Helium-4
Path Integral Quantum Monte Carlo Study of Coupling and Proximity Effects in Superfluid Helium-4 A Thesis Presented by Max T. Graves to The Faculty of the Graduate College of The University of Vermont In Partial Fullfillment of the Requirements for the Degree of Master of Science Specializing in Materials Science October, 2014 Accepted by the Faculty of the Graduate College, The University of Vermont, in partial fulfillment of the requirements for the degree of Master of Science in Materials Science. Thesis Examination Committee: Advisor Adrian Del Maestro, Ph.D. Valeri Kotov, Ph.D. Frederic Sansoz, Ph.D. Chairperson Chris Danforth, Ph.D. Dean, Graduate College Cynthia J. Forehand, Ph.D. Date: August 29, 2014 Abstract When bulk helium-4 is cooled below T = 2.18 K, it undergoes a phase transition to a su- perfluid, characterized by a complex wave function with a macroscopic phase and exhibits inviscid, quantized flow. The macroscopic phase coherence can be probed in a container filled with helium-4, by reducing one or more of its dimensions until they are smaller than the coherence length, the spatial distance over which order propagates. As this dimensional reduction occurs, enhanced thermal and quantum fluctuations push the transition to the su- perfluid state to lower temperatures. However, this trend can be countered via the proximity effect, where a bulk 3-dimensional (3d) superfluid is coupled to a low (2d) dimensional su- perfluid via a weak link producing superfluid correlations in the film at temperatures above the Kosterlitz-Thouless temperature. Recent experiments probing the coupling between 3d and 2d superfluid helium-4 have uncovered an anomalously large proximity effect, leading to an enhanced superfluid density that cannot be explained using the correlation length alone.