Event-Based Quantum Mechanics: a Context for the Emergence of Classical Information
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Arxiv:0908.1787V1 [Quant-Ph] 13 Aug 2009 Ematical Underpinning
August 13, 2009 18:17 Contemporary Physics QuantumPicturalismFinal Contemporary Physics Vol. 00, No. 00, February 2009, 1{32 RESEARCH ARTICLE Quantum picturalism Bob Coecke∗ Oxford University Computing Laboratory, Wolfson Building, Parks Road, OX1 3QD Oxford, UK (Received 01 02 2009; final version received XX YY ZZZZ) Why did it take us 50 years since the birth of the quantum mechanical formalism to discover that unknown quantum states cannot be cloned? Yet, the proof of the `no-cloning theorem' is easy, and its consequences and potential for applications are immense. Similarly, why did it take us 60 years to discover the conceptually intriguing and easily derivable physical phenomenon of `quantum teleportation'? We claim that the quantum mechanical formalism doesn't support our intuition, nor does it elucidate the key concepts that govern the behaviour of the entities that are subject to the laws of quantum physics. The arrays of complex numbers are kin to the arrays of 0s and 1s of the early days of computer programming practice. Using a technical term from computer science, the quantum mechanical formalism is `low-level'. In this review we present steps towards a diagrammatic `high-level' alternative for the Hilbert space formalism, one which appeals to our intuition. The diagrammatic language as it currently stands allows for intuitive reasoning about interacting quantum systems, and trivialises many otherwise involved and tedious computations. It clearly exposes limitations such as the no-cloning theorem, and phenomena such as quantum teleportation. As a logic, it supports `automation': it enables a (classical) computer to reason about interacting quantum systems, prove theorems, and design protocols. -
Observation of Quantum Jumps in a Single Atom
VoLUME 57, NUMBER 14 PHYSICAL REVIEW LETTERS 6 OcTosER 1986 Observation of Quantum Jumps in a Single Atom J. C. Bergquist, Randall G. Hulet, Wayne M. Itano, and D. J. Wineland Time and Frequency Division, Jtiational Bureau ofStandards, Boulder, Colorado 80303 (Received 23 June 1986) %e detect the radiatively driven electric quadrupole transition to the metastable Dsy2 state in a single, laser-cooled Hg D ion by monitoring the abrupt cessation of the fluorescence signal from the laser-excited 'Si/2 Pi~2 first resonance line. %hen the ion "jumps" back from the metastable D state to the ground S state, the S P resonance fluorescence signal immediately returns. The sta- tistical properties of the quantum jumps are investigated; for example, photon antibunching in the emission from the D state is observed ~ith 100% efficiency. PACS numbers: 32.80,Pj, 42.SO.Dv Recently, a few laboratories have trapped and radia- ground state to the 5d 6s D5/2 state near 281.5 nm. tively cooled single atoms' 4 enabling a number of The lifetime of the metastable D state has recently unique experiments to be performed. One of the ex- been measured to be about 0.1 s.'5'6 A laser tuned periments now possible is to observe the "quantum just below resonance on the highly allowed S.P transi- jumps" to and from a metastable state in a single atom tion will cool the ion and, in our case, scatter up to by monitoring of the resonance fluorescence of a 5&&10~ photons/s. By collecting even a small fraction strong transition in which at least one of the states is of the scattered photons, we can easily monitor the coupled to the metastable state. -
Dynamical Relaxation to Quantum Equilibrium
Dynamical relaxation to quantum equilibrium Or, an account of Mike's attempt to write an entirely new computer code that doesn't do quantum Monte Carlo for the first time in years. ESDG, 10th February 2010 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 What I talked about a month ago (`Exchange, antisymmetry and Pauli repulsion', ESDG Jan 13th 2010) I showed that (1) the assumption that fermions are point particles with a continuous objective existence, and (2) the equations of non-relativistic QM, allow us to deduce: • ..that a mathematically well-defined ‘fifth force', non-local in character, appears to act on the particles and causes their trajectories to differ from the classical ones. • ..that this force appears to have its origin in an objectively-existing `wave field’ mathematically represented by the usual QM wave function. • ..that indistinguishability arguments are invalid under these assumptions; rather antisymmetrization implies the introduction of forces between particles. • ..the nature of spin. • ..that the action of the force prevents two fermions from coming into close proximity when `their spins are the same', and that in general, this mechanism prevents fermions from occupying the same quantum state. This is a readily understandable causal explanation for the Exclusion principle and for its otherwise inexplicable consequences such as `degeneracy pressure' in a white dwarf star. Furthermore, if assume antisymmetry of wave field not fundamental but develops naturally over the course of time, then can see character of reason for fermionic wave functions having symmetry behaviour they do. -
Infinite Potential Show Title: Generic Show Episode #101 Date: 3/17/20 Transcribed by Daily Transcription Tre
INFINITE POTENTIAL SHOW TITLE: GENERIC SHOW EPISODE #101 DATE: 3/17/20 TRANSCRIBED BY DAILY TRANSCRIPTION_TRE 00:00:28 DAVID BOHM People talked about the world, and I said, "Where does it end?" and, uh, uh... MALE And what answer did they give? DAVID BOHM Well, they-I never, uh, I don't remember. It wasn't terribly convincing I suppose. [LAUGH] DR. DAVID C. It was, uh, a night, and we were SCHRUM walking under the stars, black sky, and he looked up to the stars, and he said, "Ordinarily, when we look to the sky and look to the stars, we think of stars as objects far out and vast spaces between them." He said, "There's another way we can look at it. We can look at the vacuum at the emptiness instead as a planum, as infinitely full rather than infinitely empty. And that the material objects themselves are like little bubbles, little vacancies in this vast sea." 00:01:25 DR. DAVID C. So David Bohm, in a sense, was SCHRUM using that view to have me look at the stars and to have a sense of the night sky all of a sudden in a different way, as one whole living organism and these little bits that we call matter as sort to just little holes in it. DR. DAVID C. He often mentioned just one other SCHRUM aspect of this, that this planum, in a cubic centimeter of the planum, there's more, uh, energy matter than in the entire visible Page 2 of 62 universe. -
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. -
Non-Locality in the Stochastic Interpretation of the Quantum Theory Annales De L’I
ANNALES DE L’I. H. P., SECTION A D. BOHM Non-locality in the stochastic interpretation of the quantum theory Annales de l’I. H. P., section A, tome 49, no 3 (1988), p. 287-296 <http://www.numdam.org/item?id=AIHPA_1988__49_3_287_0> © Gauthier-Villars, 1988, tous droits réservés. L’accès aux archives de la revue « Annales de l’I. H. P., section A » implique l’accord avec les conditions générales d’utilisation (http://www.numdam. org/conditions). Toute utilisation commerciale ou impression systématique est constitutive d’une infraction pénale. Toute copie ou impression de ce fichier doit contenir la présente mention de copyright. Article numérisé dans le cadre du programme Numérisation de documents anciens mathématiques http://www.numdam.org/ Ann. Inst. Henri Poincare, Vol. 49, n° 3, 1988, 287 Physique theorique Non-Locality in the Stochastic Interpretation of the Quantum Theory D. BOHM Department of Physics, Birkbeck College (London University), Malet Street, London WC1E 7HX ABSTRACT. - This article reviews the stochastic interpretation of the quantum theory and shows in detail how it implies non-locality. RESUME . - Cet article presente une revue de 1’interpretation stochas- tique de la theorie quantique et montre en detail en quoi elle implique une non-localite. 1. INTRODUCTION It gives me great pleasure on the occasion of Jean-Pierre Vigier’s retire- ment to recall our long period of fruitful association and to say something about the stochastic interpretation of the quantum theory, in which we worked together in earlier days. Because of requirements of space, however, this article will be a condensation of my talk (*) which was in fact based on a much more extended article by Basil Hiley and me [1 ]. -
Spin State Read-Out by Quantum Jump Technique
1 Spin State Read-Out by Quantum Jump Technique: for the Purpose of Quantum Computing E. Pazy Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel T. Calarco and P. Zoller Institut fur¨ Theoretische Physik, Universitat¨ Innsbruck, A-6020 Innsbruck, Austria Abstract—Utilizing the Pauli-blocking mechanism we in an isolated atom, self-assembled QDs are embedded show that shining circular polarized light on a singly in an underlying lattice ,i.e., a three-dimensional crystal charged quantum dot induces spin dependent fluorescence. structure. Even though the number of atoms in such Employing the quantum-jump technique we demonstrate dots is small compared to lithographically defined QDs, that this resonance luminescence, due to a spin dependent optical excitation, serves as an excellent read out mech- still this underlying lattice in which the QD is formed anism for measuring the spin state of a single electron strongly affects the single particle states through its band confined to a quantum dot. structure. Due to their discrete density of states, QDs have been I. INTRODUCTION suggested as the major building blocks for numerous quantum computing implementation schemes. These im- Semiconductor self-assembled quantum dots (QDs) plementation schemes can roughly be divided into those form spontaneously during the epitaxial growth process, which utilize the charge [2], or respectively the spin with confinement provided in all three dimensions by a [3] of charge carriers confined within a QD. Accurate high bandgap in the surrounding material (for example, measurement of a single qubit is an essential requirement see [1]). The strong confinement in such structures for the implementation of quantum computation (QC), leads to a discrete atom-like density of states which therefore highly precise methods for the measurement makes these QDs especially attractive for novel device arXiv:cond-mat/0404494v1 [cond-mat.other] 21 Apr 2004 of the spin of a QD confined charge carrier need to be applications in fields such as quantum computing, optics, devised. -
I Speculative Physics: the Ontology of Theory And
Speculative Physics: the Ontology of Theory and Experiment in High Energy Particle Physics and Science Fiction by Clarissa Ai Ling Lee Graduate Program in Literature Duke University Date: _______________________ Approved: ___________________________ N. Katherine Hayles, Co-Supervisor ___________________________ Mark C. Kruse, Co-Supervisor ___________________________ Mark B. Hansen ___________________________ Andrew Janiak ___________________________ Timothy Lenoir Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate Program in Literature in the Graduate School of Duke University 2014 i v ABSTRACT Speculative Physics: the Ontology of Theory and Experiment in High Energy Particle Physics and Science Fiction by Clarissa Ai Ling Lee Graduate Program in Literature Duke University Date:_______________________ Approved: ___________________________ N. Katherine Hayles, Co-Supervisor ___________________________ Mark C. Kruse, Co-Supervisor ___________________________ Mark B. Hansen ___________________________ Andrew Janiak ___________________________ Timothy Lenoir An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate Program in Literature in the Graduate School of Duke University 2014 i v Copyright by Clarissa Ai Ling Lee 2014 Abstract The dissertation brings together approaches across the fields of physics, critical theory, literary studies, philosophy of physics, sociology of science, and history of science to synthesize a hybrid approach for instigating more rigorous and intense cross- disciplinary interrogations between the sciences and the humanities. I explore the concept of speculation in particle physics and science fiction to examine emergent critical approaches for working in the two areas of literature and physics (the latter through critical science studies), but with the expectation of contributing new insights to media theory, critical code studies, and also the science studies of science fiction. -
10. Light and Quantum Physics
10. Light and Quantum physics Infrared radiation Infrared is light that has a wavelength longer than that of visible light. It is often called “IR.” The longest wavelength visible light that we can see has a wavelength of about 0.65 microns. Infrared light has a wavelength from 0.65 microns up to about 20 microns. Since its wavelength is longer, its frequency is lower by the same factor. We humans emit infrared radiation because we are warm. The electrons in our atoms shake, since they are not at absolute zero. A shaking electron has a shaking electric field, and a shaking electric field emits an electromagnetic wave. The effect is analogous to the emission of all other waves: shake the ground enough, and you get an earthquake wave; shake water, and you get a water wave; shake the air, and you get sound; shake the end of a slinky, and a wave will travel along it. The result is that everything emits light, except things that have temperature at absolute zero. Everything glows -- but most things emit so little light, that we don't notice. And, of course we don't notice if most of the light is in a wavelength range that is invisible to the eye. What are some of the things that we notice when they glow from heat? Here are some: candle flame; anything being heated "red hot" in a flame; the sun; the tungsten filament of a 60-watt light bulb; an oven used for baking pottery. This glowing is often referred to as "thermal radiation" or as “heat radiation.” Thermal radiation and temperature The amount of thermal radiation can be calculated using the physics laws of thermodynamics. -
There Are Quantum Jumps
Mathematics 2015, 3, 319-328; doi:10.3390/math3020319 OPEN ACCESS mathematics ISSN 2227-7390 www.mdpi.com/journal/mathematics Article There Are Quantum Jumps Erkki J. Brändas Department of Chemistry, Ångström Laboratory, Institute of Theoretical Chemistry, Uppsala University, P.O. Box 518, S-751 20 Uppsala, Sweden; E-Mail: [email protected]; Tel.: +46-0-18-471-32-68; Fax: +46-0-18-471-36-33 Academic Editor: Palle E.T. Jorgensen Received: 10 March 2015 / Accepted: 20 April 2015 / Published: 5 May 2015 Abstract: In this communication we take up the age-old problem of the possibility to incorporate quantum jumps. Unusually, we investigate quantum jumps in an extended quantum setting, but one of rigorous mathematical significance. The general background for this formulation originates in the Balslev-Combes theorem for dilatation analytic Hamiltonians and associated complex symmetric representations. The actual jump is mapped into a Jordan block of order two and a detailed derivation is discussed for the case of the emission of a photon by an atom. The result can be easily reassigned to analogous cases as well as generalized to Segrè characteristics of arbitrary order. Keywords: dilation analytic family of operators; complex symmetric representation; Segrè characteristic; Jordan block 1. Introduction In Walter Moore’s celebrated Biography, Schrödinger life and thought [1], he reproduces the famous and passionate discussion between Bohr and Schrödinger during the latter’s visit to Copenhagen in 1926. Schrödinger: “You surely must understand, Bohr, that the whole idea of quantum jumps necessarily leads to nonsense.” Bohr: “Yes, in what you say, you are completely right. -
16-1 Paul Howard
BESHARA MAGAZINE Unity in the Contemporary World ISSUE 16-1 · SUMMER 2020 INFINITE POTENTIAL: THE LIFE & IDEAS OF DAVID BOHM Film director Paul Howard talks about his new film on a remarkable scientist whose vision of wholeness and interconnectivity is now reaching a wide audience A still from the film Infinite Potential: The Life & Ideas of David Bohm avid Bohm ( 191 7–92 ) has been descri - Ear lier this year, we published an interview Dbed as one of the most significant thin- we did with him in 1991 . Now a film has been kers of the twentieth century. As a theoretical made about his life and ideas which brings to - physicist, he developed a radical approach to gether an impressive array of contemporary quantum mechanics which proposes that thinkers who are taking his vision forward. whole ness and interconnectivity are the fun - Paul Howard, its director, talks to Jane Clark damental principles of reality. In line with and Michael Cohen about the making of the this, his interests and influence extended be - film and Bohm’s importance for the world yond the confines of science to the realms of today. philosophy, spirituality and social change. u nfinite Potential begins with a story by Bohm’s one-time Istudent Dr David Schrum: “It was a night and we were walking under the stars, a black sky. David looked up at the stars and said: ‘Ordinarily, when we look to the sky and we look at the stars, we think of the stars as objects far out and that they have space in between them. -
Arxiv:1707.00609V2 [Quant-Ph] 3 Oct 2018
Bohm's approach to quantum mechanics: Alternative theory or practical picture? A. S. Sanz∗ Department of Optics, Faculty of Physical Sciences, Universidad Complutense de Madrid, Pza. Ciencias 1, Ciudad Universitaria E-28040 Madrid, Spain Since its inception Bohmian mechanics has been generally regarded as a hidden-variable theory aimed at providing an objective description of quantum phenomena. To date, this rather narrow conception of Bohm's proposal has caused it more rejection than acceptance. Now, after 65 years of Bohmian mechanics, should still be such an interpretational aspect the prevailing appraisal? Why not favoring a more pragmatic view, as a legitimate picture of quantum mechanics, on equal footing in all respects with any other more conventional quantum picture? These questions are used here to introduce a discussion on an alternative way to deal with Bohmian mechanics at present, enhancing its aspect as an efficient and useful picture or formulation to tackle, explore, describe and explain quantum phenomena where phase and correlation (entanglement) are key elements. This discussion is presented through two complementary blocks. The first block is aimed at briefly revisiting the historical context that gave rise to the appearance of Bohmian mechanics, and how this approach or analogous ones have been used in different physical contexts. This discussion is used to emphasize a more pragmatic view to the detriment of the more conventional hidden-variable (ontological) approach that has been a leitmotif within the quantum foundations. The second block focuses on some particular formal aspects of Bohmian mechanics supporting the view presented here, with special emphasis on the physical meaning of the local phase field and the associated velocity field encoded within the wave function.