|
Purification Theorem (physics)
In quantum information theory, quantum state purification refers to the process of representing a Mixed state (physics), mixed state as a Pure state, pure quantum state of higher-dimensional Hilbert space. The purification allows the original mixed state to be recovered by taking the partial trace over the additional degrees of freedom. The purification is not unique, the different purifications that can lead to the same mixed states are limited by the Schrödinger–HJW theorem. Purification is used in algorithms such as entanglement distillation, magic state distillation and algorithmic cooling. Description Let \mathcal H_S be a finite-dimensional complex number, complex Hilbert space, and consider a generic (possibly Quantum state#Mixed states, mixed) quantum state \rho defined on \mathcal H_S and admitting a decomposition of the form \rho = \sum_i p_i, \phi_i\rangle\langle\phi_i, for a collection of (not necessarily mutually orthogonal) states , \phi_i\rangle \in \mathcal H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Information Theory
Quantum information is the information of the state of a quantum system. It is the basic entity of study in quantum information theory, and can be manipulated using quantum information processing techniques. Quantum information refers to both the technical definition in terms of Von Neumann entropy and the general computational term. It is an interdisciplinary field that involves quantum mechanics, computer science, information theory, philosophy and cryptography among other fields. Its study is also relevant to disciplines such as cognitive science, psychology and neuroscience. Its main focus is in extracting information from matter at the microscopic scale. Observation in science is one of the most important ways of acquiring information and measurement is required in order to quantify the observation, making this crucial to the scientific method. In quantum mechanics, due to the uncertainty principle, non-commuting observables cannot be precisely measured simultaneously, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density Matrix
In quantum mechanics, a density matrix (or density operator) is a matrix used in calculating the probabilities of the outcomes of measurements performed on physical systems. It is a generalization of the state vectors or wavefunctions: while those can only represent pure states, density matrices can also represent mixed states. These arise in quantum mechanics in two different situations: # when the preparation of a system can randomly produce different pure states, and thus one must deal with the statistics of possible preparations, and # when one wants to describe a physical system that is entangled with another, without describing their combined state. This case is typical for a system interacting with some environment (e.g. decoherence). In this case, the density matrix of an entangled system differs from that of an ensemble of pure states that, combined, would give the same statistical results upon measurement. Density matrices are thus crucial tools in areas of quantum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundations Of Physics
''Foundations of Physics'' is a monthly journal "devoted to the conceptual bases and fundamental theories of modern physics and cosmology, emphasizing the logical, methodological, and philosophical premises of modern physical theories and procedures". The journal publishes results and observations based on fundamental questions from all fields of physics, including: quantum mechanics, quantum field theory, special relativity, general relativity, string theory, M-theory, cosmology, thermodynamics, statistical physics, and quantum gravity ''Foundations of Physics'' has been published since 1970. Its founding editors were Henry Margenau and Wolfgang Yourgrau. The 1999 Nobel laureate Gerard 't Hooft was editor-in-chief from January 2007. At that stage, it absorbed the associated journal for shorter submissions ''Foundations of Physics Letters'', which had been edited by Alwyn Van der Merwe since its foundation in 1988. Past editorial board members (which include several Nobel lau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review
''Physical Review'' is a peer-reviewed scientific journal. The journal was established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the American Physical Society (APS). The journal is in its third series, and is split in several sub-journals each covering a particular field of physics. It has a sister journal, '' Physical Review Letters'', which publishes shorter articles of broader interest. History ''Physical Review'' commenced publication in July 1893, organized by Cornell University professor Edward Nichols and helped by the new president of Cornell, J. Gould Schurman. The journal was managed and edited at Cornell in upstate New York from 1893 to 1913 by Nichols, Ernest Merritt, and Frederick Bedell. The 33 volumes published during this time constitute ''Physical Review Series I''. The American Physical Society (APS), founded in 1899, took over its publicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Letters In Mathematical Physics
''Letters in Mathematical Physics'' is a peer-reviewed scientific journal in mathematical physics published by Springer Science+Business Media. It publishes letters and longer research articles, occasionally also articles containing topical reviews. It is essentially a platform for the rapid dissemination of short contributions in the field of mathematical physics. In addition, the journal publishes contributions to modern mathematics in fields which have a potential physical application, and developments in theoretical physics which have potential mathematical impact. The editors are Volker Bach, Edward Frenkel, Maxim Kontsevich, Dirk Kreimer, Nikita Nekrasov, Massimo Porrati, and Daniel Sternheimer. Abstracting and indexing The following services abstract or index ''Letters in Mathematical Physics'': Academic OneFile, Academic Search, Astrophysics Data System, Chemical Abstracts Service, Current Contents/Physical, Chemical and Earth Sciences, Current Index to Statistics, EBSCO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edwin Thompson Jaynes
Edwin Thompson Jaynes (July 5, 1922 – April 30, 1998) was the Wayman Crow Distinguished Professor of Physics at Washington University in St. Louis. He wrote extensively on statistical mechanics and on foundations of probability and statistical inference, initiating in 1957 the maximum entropy interpretation of thermodynamics as being a particular application of more general Bayesian/ information theory techniques (although he argued this was already implicit in the works of Josiah Willard Gibbs). Jaynes strongly promoted the interpretation of probability theory as an extension of logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o .... In 1963, together with his doctoral student Fred Cummings, he modeled the evolution of a two-level atom in an electromagnetic field, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicolas Gisin
Nicolas Gisin (born 1952) is a Swiss physicist and professor at the University of Geneva, working on the foundations of quantum mechanics, quantum information, and communication. His work includes both experimental and theoretical physics. He has contributed work in the fields of experimental quantum cryptography and long-distance quantum communication over standard telecom optical fibers. He also co-founded ID Quantique, a company that provides quantum-based technologies. Biography Nicolas Gisin was born in Geneva on 29 May 1952. He received a degree in mathematics and a master's degree in physics before receiving his Ph.D. in Physics from the University of Geneva in 1981. His dissertation concerned quantum and statistical physics. After several years in the software and optical communication industries, Gisin joined thGroup of Applied Physics at the University of Genevain 1994, where he started working in optics. Since 2000, he has been the Director of the Department of Appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics Letters A
''Physics Letters'' was a scientific journal published from 1962 to 1966, when it split in two series now published by Elsevier Elsevier ( ) is a Dutch academic publishing company specializing in scientific, technical, and medical content. Its products include journals such as ''The Lancet'', ''Cell (journal), Cell'', the ScienceDirect collection of electronic journals, ...: *''Physics Letters A'': condensed matter physics, theoretical physics, nonlinear science, statistical physics, mathematical and computational physics, general and cross-disciplinary physics (including foundations), atomic, molecular and cluster physics, plasma and fluid physics, optical physics, biological physics and nanoscience. *''Physics Letters B'': nuclear physics, theoretical nuclear physics, experimental high-energy physics, theoretical high-energy physics, and astrophysics. ''Physics Letters B'' is part of the SCOAP3 initiative. References See also * List of periodicals published by Elsevier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Wootters
William "Bill" Kent Wootters is an American theoretical physicist, and one of the founders of the field of quantum information theory. In a 1982 joint paper with Wojciech H. Zurek, Wootters proved the no-cloning theorem, at the same time as Dennis Dieks, and independently of James L. Park who had formulated the no-cloning theorem in 1970. He is known for his contributions to the theory of quantum entanglement including quantitative measures of it, entanglement-assisted communication (notably quantum teleportation, discovered by Wootters and collaborators in 1993) and entanglement distillation. The term ''qubit,'' denoting the basic unit of quantum information, originated in a conversation between Wootters and Benjamin Schumacher in 1992. He earned a B.S. from Stanford University in 1973, and his Ph.D. from the University of Texas at Austin in 1980. His thesis was titled ''The Acquisition of Information from Quantum Measurements,'' and Linda Reichl was his doctoral advisor, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Jozsa
Richard Jozsa is an Australian mathematician who holds the Leigh Trapnell Chair in Quantum Physics at the University of Cambridge. He is a fellow of King's College, Cambridge, where his research investigates quantum information science. A pioneer of his field, he is the co-author of the Deutsch–Jozsa algorithm and one of the co-inventors of quantum teleportation. Education Jozsa received his Doctor of Philosophy degree on twistor theory at Oxford, under the supervision of Roger Penrose. Career and research Jozsa has held previous positions at the University of Bristol, the University of Plymouth and the Université de Montréal. Awards and honours His work was recognised in 2004 by the London Mathematical Society with the award of the Naylor Prize for 'his fundamental contributions to the new field of quantum information science'. Since 2016, Jozsa is a member of the Academia Europaea The Academia Europaea is a pan-European Academy of humanities, letters, law, and sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lane P
In road transport, a lane is part of a roadway that is designated to be used by a single line of vehicles to control and guide drivers and reduce traffic conflicts. Most public roads (highways) have at least two lanes, one for traffic in each direction, separated by lane markings. On multilane roadways and busier two-lane roads, lanes are designated with road surface markings. Major highways often have two multi-lane roadways separated by a median. Some roads and bridges that carry very low volumes of traffic are less than wide, and are only a single lane wide. Vehicles travelling in opposite directions must slow or stop to pass each other. In rural areas, these are often called country lanes. In urban areas, alleys are often only one lane wide. Urban and suburban one lane roads are often designated for one-way traffic. History For much of human history, roads did not need lane markings because most people walked or rode horses at relatively slow speeds. However, when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
