The Age of Entanglement
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Dear Fellow Quantum Mechanics;
Dear Fellow Quantum Mechanics Jeremy Bernstein Abstract: This is a letter of inquiry about the nature of quantum mechanics. I have been reflecting on the sociology of our little group and as is my wont here are a few notes. I see our community divided up into various subgroups. I will try to describe them beginning with a small group of elderly but distinguished physicist who either believe that there is no problem with the quantum theory and that the young are wasting their time or that there is a problem and that they have solved it. In the former category is Rudolf Peierls and in the latter Phil Anderson. I will begin with Peierls. In the January 1991 issue of Physics World Peierls published a paper entitled “In defence of ‘measurement’”. It was one of the last papers he wrote. It was in response to his former pupil John Bell’s essay “Against measurement” which he had published in the same journal in August of 1990. Bell, who had died before Peierls’ paper was published, had tried to explain some of the difficulties of quantum mechanics. Peierls would have none of it.” But I do not agree with John Bell,” he wrote,” that these problems are very difficult. I think it is easy to give an acceptable account…” In the rest of his short paper this is what he sets out to do. He begins, “In my view the most fundamental statement of quantum mechanics is that the wave function or more generally the density matrix represents our knowledge of the system we are trying to describe.” Of course the wave function collapses when this knowledge is altered. -
Multi-Dimensional Entanglement Transport Through Single-Mode Fibre
Multi-dimensional entanglement transport through single-mode fibre Jun Liu,1, ∗ Isaac Nape,2, ∗ Qianke Wang,1 Adam Vall´es,2 Jian Wang,1 and Andrew Forbes2 1Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China. 2School of Physics, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa (Dated: April 8, 2019) The global quantum network requires the distribution of entangled states over long distances, with significant advances already demonstrated using entangled polarisation states, reaching approxi- mately 1200 km in free space and 100 km in optical fibre. Packing more information into each photon requires Hilbert spaces with higher dimensionality, for example, that of spatial modes of light. However spatial mode entanglement transport requires custom multimode fibre and is lim- ited by decoherence induced mode coupling. Here we transport multi-dimensional entangled states down conventional single-mode fibre (SMF). We achieve this by entangling the spin-orbit degrees of freedom of a bi-photon pair, passing the polarisation (spin) photon down the SMF while ac- cessing multi-dimensional orbital angular momentum (orbital) subspaces with the other. We show high fidelity hybrid entanglement preservation down 250 m of SMF across multiple 2 × 2 dimen- sions, demonstrating quantum key distribution protocols, quantum state tomographies and quantum erasers. This work offers an alternative approach to spatial mode entanglement transport that fa- cilitates deployment in legacy networks across conventional fibre. Entanglement is an intriguing aspect of quantum me- chanics with well-known quantum paradoxes such as those of Einstein-Podolsky-Rosen (EPR) [1], Hardy [2], and Leggett [3]. -
On Monte Carlo Time-Dependent Variational Principles
On Monte Carlo Time-Dependent Variational Principles Von der QUEST-Leibniz-Forschungsschule der Gottfried Wilhelm Leibniz Universit¨atHannover zur Erlangung des akademischen Grades Doktor der Naturwissenschaften { Doctor rerum naturalium { genehmigte Dissertation von FABIANWOLFGANGG UNTERTRANSCHEL¨ Geboren am 10.01.1987 in Gehrden 2016 0 Erstpr¨ufer : Prof. Dr. Reinhard F. Werner Zweitpr¨ufer : Prof. Dr. Klemens Hammerer Beratendes Mitglied des Pr¨ufungsausschusses : Prof. Dr. Tobias J. Osborne Vorsitzender des Pr¨ufungsausschusses : Prof. Dr. Rolf Haug Tag der Promotion: 17. Dezember 2015 On Monte Carlo Time-Dependent Variational Principles Fabian W. G. Transchel Abstract The present dissertation is concerned with the development and implementation of a novel scheme for quantitative, numeric approximation of the dynamics of quantum lattice systems based on the Time-Dependent Variational Principle together with Monte Carlo techniques in order to include dissipative interactions. The specific implementation is demonstrated on both common and not yet in-detail explored Heisenberg- and Fermi-Hubbard models in one and two dimensions. Additionally, the technical requirements regarding computational complexity and capacity are discussed, especially with regards toward parallelizable components of the imple- mentation. Concluding remarks include prospects with respect to application and extension of the presented methods. Keywords: Monte Carlo method, Dissipative Dynamics, Lindblad Equation iii Zusammenfassung Die vorliegende Dissertation befasst sich mit der Entwicklung und Umsetzung eines neuartigen Schemas zur quantitativen numerischen N¨aherung der Dynamik von Quantengittersystemen auf Grundlage des zeitabh¨angigenVariationsprinzips unter Zuhilfenahme von Monte-Carlo-Techniken zur Einbeziehung von dissipativen Wech- selwirkungen. Die Implementierung wird anhand von Beispielen f¨urHeisenberg- und Fermi-Hubbard-Modellen in einer und zwei Dimensionen gezeigt und erl¨autert. -
Cracking the Einstein Code: Relativity and the Birth of Black Hole Physics, with an Afterword by Roy Kerr / Fulvio Melia
CRA C K I N G T H E E INSTEIN CODE @SZObWdWbgO\RbVS0W`bV]T0ZOQY6]ZS>VgaWQa eWbVO\/TbS`e]`RPg@]gS`` fulvio melia The University of Chicago Press chicago and london fulvio melia is a professor in the departments of physics and astronomy at the University of Arizona. He is the author of The Galactic Supermassive Black Hole; The Black Hole at the Center of Our Galaxy; The Edge of Infinity; and Electrodynamics, and he is series editor of the book series Theoretical Astrophysics published by the University of Chicago Press. The University of Chicago Press, Chicago 60637 The University of Chicago Press, Ltd., London © 2009 by The University of Chicago All rights reserved. Published 2009 Printed in the United States of America 18 17 16 15 14 13 12 11 10 09 1 2 3 4 5 isbn-13: 978-0-226-51951-7 (cloth) isbn-10: 0-226-51951-1 (cloth) Library of Congress Cataloging-in-Publication Data Melia, Fulvio. Cracking the Einstein code: relativity and the birth of black hole physics, with an afterword by Roy Kerr / Fulvio Melia. p. cm. Includes bibliographical references and index. isbn-13: 978-0-226-51951-7 (cloth: alk. paper) isbn-10: 0-226-51951-1 (cloth: alk. paper) 1. Einstein field equations. 2. Kerr, R. P. (Roy P.). 3. Kerr black holes—Mathematical models. 4. Black holes (Astronomy)—Mathematical models. I. Title. qc173.6.m434 2009 530.11—dc22 2008044006 To natalina panaia and cesare melia, in loving memory CONTENTS preface ix 1 Einstein’s Code 1 2 Space and Time 5 3 Gravity 15 4 Four Pillars and a Prayer 24 5 An Unbreakable Code 39 6 Roy Kerr 54 7 The Kerr Solution 69 8 Black Hole 82 9 The Tower 100 10 New Zealand 105 11 Kerr in the Cosmos 111 12 Future Breakthrough 121 afterword 125 references 129 index 133 PREFACE Something quite remarkable arrived in my mail during the summer of 2004. -
Sacred Rhetorical Invention in the String Theory Movement
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Communication Studies Theses, Dissertations, and Student Research Communication Studies, Department of Spring 4-12-2011 Secular Salvation: Sacred Rhetorical Invention in the String Theory Movement Brent Yergensen University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/commstuddiss Part of the Speech and Rhetorical Studies Commons Yergensen, Brent, "Secular Salvation: Sacred Rhetorical Invention in the String Theory Movement" (2011). Communication Studies Theses, Dissertations, and Student Research. 6. https://digitalcommons.unl.edu/commstuddiss/6 This Article is brought to you for free and open access by the Communication Studies, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Communication Studies Theses, Dissertations, and Student Research by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. SECULAR SALVATION: SACRED RHETORICAL INVENTION IN THE STRING THEORY MOVEMENT by Brent Yergensen A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy Major: Communication Studies Under the Supervision of Dr. Ronald Lee Lincoln, Nebraska April, 2011 ii SECULAR SALVATION: SACRED RHETORICAL INVENTION IN THE STRING THEORY MOVEMENT Brent Yergensen, Ph.D. University of Nebraska, 2011 Advisor: Ronald Lee String theory is argued by its proponents to be the Theory of Everything. It achieves this status in physics because it provides unification for contradictory laws of physics, namely quantum mechanics and general relativity. While based on advanced theoretical mathematics, its public discourse is growing in prevalence and its rhetorical power is leading to a scientific revolution, even among the public. -
Scientific Report for the Year 2000
The Erwin Schr¨odinger International Boltzmanngasse 9 ESI Institute for Mathematical Physics A-1090 Wien, Austria Scientific Report for the Year 2000 Vienna, ESI-Report 2000 March 1, 2001 Supported by Federal Ministry of Education, Science, and Culture, Austria ESI–Report 2000 ERWIN SCHRODINGER¨ INTERNATIONAL INSTITUTE OF MATHEMATICAL PHYSICS, SCIENTIFIC REPORT FOR THE YEAR 2000 ESI, Boltzmanngasse 9, A-1090 Wien, Austria March 1, 2001 Honorary President: Walter Thirring, Tel. +43-1-4277-51516. President: Jakob Yngvason: +43-1-4277-51506. [email protected] Director: Peter W. Michor: +43-1-3172047-16. [email protected] Director: Klaus Schmidt: +43-1-3172047-14. [email protected] Administration: Ulrike Fischer, Eva Kissler, Ursula Sagmeister: +43-1-3172047-12, [email protected] Computer group: Andreas Cap, Gerald Teschl, Hermann Schichl. International Scientific Advisory board: Jean-Pierre Bourguignon (IHES), Giovanni Gallavotti (Roma), Krzysztof Gawedzki (IHES), Vaughan F.R. Jones (Berkeley), Viktor Kac (MIT), Elliott Lieb (Princeton), Harald Grosse (Vienna), Harald Niederreiter (Vienna), ESI preprints are available via ‘anonymous ftp’ or ‘gopher’: FTP.ESI.AC.AT and via the URL: http://www.esi.ac.at. Table of contents General remarks . 2 Winter School in Geometry and Physics . 2 Wolfgang Pauli und die Physik des 20. Jahrhunderts . 3 Summer Session Seminar Sophus Lie . 3 PROGRAMS IN 2000 . 4 Duality, String Theory, and M-theory . 4 Confinement . 5 Representation theory . 7 Algebraic Groups, Invariant Theory, and Applications . 7 Quantum Measurement and Information . 9 CONTINUATION OF PROGRAMS FROM 1999 and earlier . 10 List of Preprints in 2000 . 13 List of seminars and colloquia outside of conferences . -
Is There Ontology After Bell's Theorem?
IS THERE ONTOLOGY AFTER BELL'S THEOREM? A Speech given to the Philosophical Club of Cleveland February 14, 1984 By John Heighway 1 IS THERE ONTOLOGY AFTER BELL'S THEOREM? I feel that it’s unfair to use a title containing a generally unfamiliar term, in this case "Bell's Theorem," without promptly giving some explanation. It happens that logic demands a rather lengthy lead-in, so let me quote here, as a sort of "jacket blurb" introduction, the abstract of the excellent review article on Bell's Theorem, by John Clauser and Abner Shimony. Bell's Theorem represents a significant advance in understanding the conceptual foundations of quantum mechanics. The theorem shows that essentially all local theories of natural phenomena that are formulated within the framework of realism may be tested using a single experimental arrangement. Moreover, the predictions by these theories must significantly differ from those by quantum mechanics. Experimental results evidently refute the theorem's predictions for these theories and favour those of quantum mechanics. The conclusions are philosophically startling: either one must totally abandon the realistic philosophy of most working scientists, or dramatically revise our concept of space-time. If I were permitted to edit this statement, I would just add the words "or both" to the final sentence. Ontology is a branch of metaphysics dealing with theories of reality or being. Almost all scientists, past and present, have embraced without reservation the theory called realism, which holds that external reality exists and possesses definite properties, altogether independently of whether or not those properties are observed by someone. -
Voigt Transformations in Retrospect: Missed Opportunities?
Voigt transformations in retrospect: missed opportunities? Olga Chashchina Ecole´ Polytechnique, Palaiseau, France∗ Natalya Dudisheva Novosibirsk State University, 630 090, Novosibirsk, Russia† Zurab K. Silagadze Novosibirsk State University and Budker Institute of Nuclear Physics, 630 090, Novosibirsk, Russia.‡ The teaching of modern physics often uses the history of physics as a didactic tool. However, as in this process the history of physics is not something studied but used, there is a danger that the history itself will be distorted in, as Butterfield calls it, a “Whiggish” way, when the present becomes the measure of the past. It is not surprising that reading today a paper written more than a hundred years ago, we can extract much more of it than was actually thought or dreamed by the author himself. We demonstrate this Whiggish approach on the example of Woldemar Voigt’s 1887 paper. From the modern perspective, it may appear that this paper opens a way to both the special relativity and to its anisotropic Finslerian generalization which came into the focus only recently, in relation with the Cohen and Glashow’s very special relativity proposal. With a little imagination, one can connect Voigt’s paper to the notorious Einstein-Poincar´epri- ority dispute, which we believe is a Whiggish late time artifact. We use the related historical circumstances to give a broader view on special relativity, than it is usually anticipated. PACS numbers: 03.30.+p; 1.65.+g Keywords: Special relativity, Very special relativity, Voigt transformations, Einstein-Poincar´epriority dispute I. INTRODUCTION Sometimes Woldemar Voigt, a German physicist, is considered as “Relativity’s forgotten figure” [1]. -
A Question of Quantum Reality 24 September 2020
A question of quantum reality 24 September 2020 virtuality. Bell spent most of his working life at CERN in Geneva, Switzerland, and Bertlmann first met him when he took up a short-term fellowship there in 1978. Bell had first presented his theorem in a seminal paper published in 1964, but this was largely neglected until the 1980s and the introduction of quantum information. Bertlmann discusses the concept of Bell inequalities, which arise through thought experiments in which a pair of spin-½ particles propagate in opposite directions and are measured Credit: Pixabay/CC0 Public Domain by independent observers, Alice and Bob. The Bell inequality distinguishes between local realism—the 'common sense' view in which Alice's observations do not depend on Bob's, and vice versa—and Physicist Reinhold Bertlmann of the University of quantum mechanics, or, specifically, quantum Vienna, Austria has published a review of the work entanglement. Two quantum particles, such as of his late long-term collaborator John Stewart Bell those in the Alice-Bob situation, are entangled of CERN, Geneva in EPJ H. This review, "Real or when the state measured by one observer Not Real: that is the question," explores Bell's instantaneously influences that of the other. This inequalities and his concepts of reality and theory is the basis of quantum information. explains their relevance to quantum information and its applications. And quantum information is no longer just an abstruse theory. It is finding applications in fields as John Stewart Bell's eponymous theorem and diverse as security protocols, cryptography and inequalities set out, mathematically, the contrast quantum computing. -
Final Copy 2020 11 26 Stylia
This electronic thesis or dissertation has been downloaded from Explore Bristol Research, http://research-information.bristol.ac.uk Author: Stylianou, Nicos Title: On 'Probability' A Case of Down to Earth Humean Propensities General rights Access to the thesis is subject to the Creative Commons Attribution - NonCommercial-No Derivatives 4.0 International Public License. A copy of this may be found at https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode This license sets out your rights and the restrictions that apply to your access to the thesis so it is important you read this before proceeding. Take down policy Some pages of this thesis may have been removed for copyright restrictions prior to having it been deposited in Explore Bristol Research. However, if you have discovered material within the thesis that you consider to be unlawful e.g. breaches of copyright (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please contact [email protected] and include the following information in your message: •Your contact details •Bibliographic details for the item, including a URL •An outline nature of the complaint Your claim will be investigated and, where appropriate, the item in question will be removed from public view as soon as possible. On ‘Probability’ A Case of Down to Earth Humean Propensities By NICOS STYLIANOU Department of Philosophy UNIVERSITY OF BRISTOL A dissertation submitted to the University of Bristol in ac- cordance with the requirements of the degree of DOCTOR OF PHILOSOPHY in the Faculty of Arts. -
Disproof of John Stewart Bell
Disproof of John Stewart Bell T. Liffert 4th October 2020 Abstract The proof of John Stewart Bell [1] [2] is based on wrong premises. A deterministic model for a hidden mechanism with an parameter λ is therefor possible. This model is possible by an integration of the experimental context into the wave function 1 The basic experiment The following considerations are based on an experiment with a pair of en- tangled photons, each of them meets a polarisation filter. The crucial phe- nomenon consists of the fact, that, if the polarisation filters are adjusted identically, the photons react always identically: Either both will be ab- sorbed or both will be transmitted. For the angular difference Φ between the polarisation filter adjustments the probability, that both photons give identi- cal measurement results, is the square of the cosine of that angular difference (law of Malus)[3]. The set of the possible measurement results is a binary one, it can be referred to by expressions like f0; 1g or f+1; −1g. For later considerations of serie experiments and related expected values I use the set f+1; −1g, for the treatment of the proof variant according to Wigner-Bell I choose the set f0; 1g. I use the following assignments for measurement results and eigenstates • 0 j0i ! 1 • 1 j1i ! −1 May α denote the measurement result of the left photon and β the one of the right photon. The upper proposition for the conditional probability P of identical measurement results given the angular difference Φ one would write like this: P (α = βjΦ) = cos2 Φ (1) 1 1.1 The quantum mechanical doctrine In the literature that I know there is a strict separation between the quantum state jΨi of the pair of photons on the one hand and the experimental context, consisting of nothing more than the angular difference of the polarisation filters or the polarizers, on the other hand. -
A Contribuição De Chien Shiung Wu Para a Teoria Quântica
UNIVERSIDADE FEDERAL DA BAHIA UNIVERSIDADE ESTADUAL DE FEIRA DE SANTANA PROGRAMA DE PÓS-GRADUAÇÃO EM ENSINO, FILOSOFIA E HISTÓRIA DAS CIÊNCIAS ANGEVALDO MENEZES MAIA FILHO PARA UMA HISTÓRIA DAS MULHERES NA CIÊNCIA: A CONTRIBUIÇÃO DE CHIEN SHIUNG WU PARA A TEORIA QUÂNTICA Salvador 2018 ANGEVALDO MENEZES MAIA FILHO PARA UMA HISTÓRIA DAS MULHERES NA CIÊNCIA: A CONTRIBUIÇÃO DE CHIEN SHIUNG WU PARA A TEORIA QUÂNTICA Dissertação apresentada ao Programa de Pós- Graduação em Ensino, Filosofia e História das Ciências, da Universidade Federal da Bahia e da Universidade Estadual de Feira de Santana como requisito parcial para a obtenção do título de Mestre em Ensino, Filosofia e História das Ciências. Orientadora: Profa. Dra. Indianara Lima Silva Salvador 2018 ANGEVALDO MENEZES MAIA FILHO PARA UMA HISTÓRIA DAS MULHERES NA CIÊNCIA: A CONTRIBUIÇÃO DE CHIEN SHIUNG WU PARA A TEORIA QUÂNTICA Dissertação apresentada como requisito parcial para obtenção do grau de mestre em 19 de abril de 2018, Programa de Pós-Graduação em Ensino, Filosofia e História das Ciências, da Universidade Federal da Bahia e da Universidade Estadual de Feira de Santana. 19 de abril de 2018 Banca Examinadora _______________________________________________ Professora Doutora Indianara Lima Silva _______________________________________________ Professora Doutora Maria Margaret Lopes _______________________________________________ Professor Doutor Olival Freire Júnior AGRADECIMENTOS Como não poderia deixar de ser, os agradecimentos revelam o quão importante são as pessoas que nos cercam e o quanto pode ser difícil, no meu caso, absolutamente impossível, realizar um trabalho individualmente. Agradeço a Josenice Assunção Maia e Angevaldo Maia, pessoas que tive a sorte de ter enquanto genitores me apoiando incondicionalmente desde sempre, confiando e acreditando nas minhas escolhas, a maior e inesgotável fonte de amor que pude encontrar na vida.