The Quantum Handshake John G
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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. -
ROBERT SERBER March 14, 1909–June 1, 1997
NATIONAL ACADEMY OF SCIENCES ROBE R T S E R BE R 1 9 0 9 — 1 9 9 7 A Biographical Memoir by ROBE R T P . Cr E A S E Any opinions expressed in this memoir are those of the author and do not necessarily reflect the views of the National Academy of Sciences. Biographical Memoir COPYRIGHT 2008 NATIONAL ACADEMY OF SCIENCES WASHINGTON, D.C. AIP Emilio Segre Visual Archives ROBERT SERBER March 14, 1909–June 1, 1997 BY ROBE RT P . CREASE OBERT SERBER (elected to the NAS in 1952) was one of Rthe leading theorists during the golden age of U.S. physics. He entered graduate school in 190 before such key discoveries as the neutron, positron, and deuteron and prior to the development of the principal tool of nuclear and high-energy physics, the particle accelerator. He retired from the Columbia University Physics Department (as its chairman) in 1978 after completion of the standard model of elementary particle physics, which comprises almost all known particles and forces in a single package, and which has proven hard to surpass. Shy and unostentatious, Serber did not mind being the detached spectator, and did not care when he was occasionally out of step with the mainstream, whether in politics or phys- ics. Nevertheless, others regularly counted on him for advice: he was an insider among insiders. He seemed to carry the entire field of physics in his head, and his particular strength was a synthetic ability. He could integrate all that was known of an area of physics and articulate it back to others clearly and consistently, explaining the connection of each part to the rest. -
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. -
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. -
Teller's Technical Nemeses: the American Hydrogen Bomb and Its Development Within a Technological Infrastructure
PHIL & TECH 3:3 Spring 1998 Fitzpatrick, Teller's Technical Nemeses/10 TELLER'S TECHNICAL NEMESES: THE AMERICAN HYDROGEN BOMB AND ITS DEVELOPMENT WITHIN A TECHNOLOGICAL INFRASTRUCTURE Anne Fitzpatrick, George Washington University In World War II the U.S. Army contracted the University of Pennsylvania's Moore School of Engineering to develop a new, large electronic computer—among the first of its kind—in hopes that the machine would be able to perform ballistics calculations for the war effort. The machine was not completed before the end of the war, however, and the Army was not even the first group to utilize the machine. The first calculation ever run on the Electronic Numeric Integrator and Calculator (or ENIAC, as it was known), was for the Los Alamos nuclear weapons laboratory. The "Super problem" was the first attempt to calculate the feasibility of a thermonuclear bomb. The problem, however, was too complicated for the ENIAC with its 1000 bits of memory and 18,000 vacuum tubes, and only a very simplified version of the calculation was run, revealing very little about how such a weapon might work. Although Los Alamos was exploring hydrogen weapons during and right after the Second World War, why did the U.S. not successfully test a thermonuclear bomb until 1952? I will argue that the American thermonuclear weapons program was, early on, entrenched in a technological infrastructure which affected the pace and initial results of the project, demonstrating how one particular aspect of this infrastructure—computing—influenced the practice of nuclear weapons research, design, and development. -
Oppenheimer: a Life April 22, 1904-February 18, 1967
Oppenheimer: A Life April 22, 1904-February 18, 1967 an online centennial exhibit of J. Robert Oppenheimer http://ohst.berkeley.edu/oppenheimer/exhibit/ This print edition of the online exhibit is free for use, reproduction, and distribution for educational purposes as long as this cover page and the acknowlegments page are included. It may not be altered or sold. For other usage questions, please contact the Office for History of Science and Technology, Univer- sity of California, Berkeley, at http://ohst.berkeley.edu. All image copyrights are retained by their hold- ers. © 2004 by The Regents of the University of California. 1 Oppenheimer: A Life April 22, 1904-February 18, 1967 Introduction As Alice Kimball Smith and Charles Weiner have noted, “Part of Oppenheimer’s attraction, at first for his friends and later for the public, was that he did not project the popularly held image of the scientist as cold, objective, rational and therefore above human frailty, an image that scientists themselves fostered by underplaying their per- sonal histories and the disorder that precedes the neat scientific conclusion.” There is a cacophony of conflicting descriptions of Oppenheimer – as friends have remembered him, as historians have analyzed him. He has been labeled both warm and cold, friendly and condescending, affable as well as hurtful. Learning Sanskrit and cultivating the air of an aesthete, as a young professor he stretched the bounds of the scientist’s persona. Yet in the space of a decade, the otherworldly theorist was transformed into a political insider par excellence. His fellow scientists remembered him as a visionary and capable leader at Los Alamos, while his security hearing brought to light foolish mistakes in judgment and human relationships. -
Opening Paragraph • State for Which Job You’Re Applying, and Where You Saw the Ad
2018 Physics Nobel Prize Tomorrow! • Leading contenders: • Yakir Aharonov and Michael Berry, Geometric phases in Quantum Mechanics • John Clauser and Anton Zeilinger, Bell’s Inequalities and Entanglement • Akihiro Kojima, Kenjiro Teshima, Yasuo Shirai and Tsutomu Miyasaka, Use of Perovskite and organometals in solar cells • Lene Hau, Slowing of light (to 50 km/h) • David Smith and John Pendry, Development of “metamaterials” (invisibility cloaks!) Presenting Your Best Side! Resumes, Cover Letters, Personal Statements, and Elevator Speeches PHYS 480 – Fall 2018 Curriculum Vitaes (CVs) • A short (one to two page) summary of your skills and experience • Should include: 1. Full name / address / email / website 2. Education 3. Work Experience 4. Skills and Knowledge Cover Letters • Opening paragraph • State for which job you’re applying, and where you saw the ad. Describe your interest and enthusiasm for the job. If you have any particular connections to the company, you may want to mention them up front. • Make it a captivating read! • Middle paragraph (or two) • Clearly connect your past to the job opening. Talk about how your past experiences gave you the necessary skills and knowledge for this particular job. Focus on what you can bring to the company, not what the job will do for you. • Closing paragraph • Thank the person you’re writing for their time / attention. • Reiterate your enthusiasm for joining the company. • Express your eagerness to meet in person to discuss the opportunity. Personal Statements • An opportunity for you to present yourself to the graduate (medical) school application committee! • Similar to the cover letter for job applications (so make the first paragraph count!) • May be a deciding factor to a committee looking at a borderline acceptance. -
Violation of an Augmented Set of Leggett-Garg Inequalities and the Implementation of a Continuous in Time Velocity Measurement
Violation of an augmented set of Leggett-Garg inequalities and the implementation of a continuous in time velocity measurement by Shayan-Shawn Majidy A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Masters of Science in Physics (Quantum Information) Waterloo, Ontario, Canada, 2019 c Shayan-Shawn Majidy 2019 I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract Macroscopic realism (MR) is the view that a system may possess definite properties at any time independent of past or future measurements, and may be tested experimentally using the Leggett-Garg inequalities (LGIs). In this work we advance the study of LGIs in two ways using experiments carried out on a nuclear magnetic resonance spectrometer. Firstly, we addresses the fact that the LGIs are only necessary conditions for MR but not sufficient ones. We implement a recently-proposed test of necessary and sufficient conditions for MR which consists of a combination of the original four three-time LGIs augmented with a set of twelve two-time LGIs. We explore different regimes in which the two- and three-time LGIs may each be satisfied or violated. Secondly, we implement a recent proposal for a measurement protocol which determines the temporal correlation functions in an approximately non-invasive manner. It employs a measurement of the velocity of a dichotomic variable Q, continuous in time, from which a possible sign change of Q may be determined in a single measurement of an ancilla coupled to the velocity. -
A Bibliography of Publications By, and About, Edward Teller
A Bibliography of Publications by, and about, Edward Teller Nelson H. F. Beebe University of Utah Department of Mathematics, 110 LCB 155 S 1400 E RM 233 Salt Lake City, UT 84112-0090 USA Tel: +1 801 581 5254 FAX: +1 801 581 4148 E-mail: [email protected], [email protected], [email protected] (Internet) WWW URL: http://www.math.utah.edu/~beebe/ 17 March 2021 Version 1.177 Title word cross-reference + [KT48, TT35a]. $100 [Smi85b]. $12.95 [Edg91]. $19.50 [Oli69]. $24.95 [Car91]. $3.50 [Dys58]. $30.00 [Kev03]. $32.50 [Edg91]. $35 [Cas01b, Cas01a]. $35.00 [Dys02a, Wat03]. $39.50 [Edg91]. $50 [Ano62]. − 7 $8.95 [Edg91]. = [TT35a]. [BJT69]. [CT41]. 2 [SST71, ST39b, TT35a]. 3 [HT39a]. 4 [TT35a]. 6 [TT35a]. β [GT36, GT37, HS19]. λ2000 [MT42]. SU(3) [GT85]. -Disintegration [GT36]. -Mesons [BJT69]. -Transformation [GT37]. 0 [Cas01b, Cas01a, Dys02a]. 0-7382-0532-X [Cas01b, Cas01a, Dys02a]. 0-8047-1713-3 [Edg91]. 0-8047-1714-1 [Edg91]. 0-8047-1721-4 [Edg91]. 0-8047-1722-2 [Edg91]. 1 [Har05]. 1-86094-419-1 [Har05]. 1-903985-12-9 [Tho03]. 100th 1 2 [KRW05, Tel93d]. 17.25 [Pei87]. 1930 [BW05]. 1930/41 [Fer68]. 1939 [Sei90]. 1939-1945 [Sei90]. 1940 [TT40]. 1941 [TGF41]. 1942 [KW93]. 1945 [Sei90]. 1947 [Sei90]. 1947-1977 [Sei90]. 1948 [Tel49a]. 1950s [Sei90]. 1957 [Tel57b]. 1960s [Mla98]. 1963 [Szi87]. 1973 [Kur73]. 1977 [Sei90]. 1979 [WT79]. 1990s [AB88, CT90a, Tel96b]. 1991 [MB92]. 1992 [GER+92]. 1995 [Tel95a]. 20 [Goe88]. 2003 [Dys09, LBB+03]. 2008 [LV10]. 20th [Mar10, New03d]. 28 [Tel57b]. 3 [Dic79]. 40th [MKR87]. 411-415 [Ber03b].