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Local Hidden-variable Theory
In the interpretation of quantum mechanics, a local hidden-variable theory is a hidden-variable theory that satisfies the principle of locality. These models attempt to account for the probabilistic features of quantum mechanics via the mechanism of underlying but inaccessible variables, with the additional requirement that distant events be statistically independent. The mathematical implications of a local hidden-variable theory with regards to quantum entanglement were explored by physicist John Stewart Bell, who in 1964 proved that broad classes of local hidden-variable theories cannot reproduce the correlations between measurement outcomes that quantum mechanics predicts, a result since confirmed by a range of detailed Bell test experiments. Models Single qubit A collection of related theorems, beginning with Bell's proof in 1964, show that quantum mechanics is incompatible with local hidden variables. However, as Bell pointed out, restricted sets of quantum phenomena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interpretations Of Quantum Mechanics
An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics might correspond to experienced reality. Quantum mechanics has held up to rigorous and extremely precise tests in an extraordinarily broad range of experiments. However, there exist a number of contending schools of thought over their interpretation. These views on interpretation differ on such fundamental questions as whether quantum mechanics is determinism, deterministic or stochastic, Principle_of_locality, local or Quantum_nonlocality, non-local, which elements of quantum mechanics can be considered real, and what the nature of measurement in quantum mechanics, measurement is, among other matters. While some variation of the Copenhagen interpretation is commonly presented in textbooks, many other interpretations have been developed. Despite nearly a century of debate and experiment, no consensus has been reached among physicists and Philosophy of physics, philosophe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gleason's Theorem
In mathematical physics, Gleason's theorem shows that the rule one uses to calculate probabilities in quantum physics, the Born rule, can be derived from the usual mathematical representation of measurements in quantum physics together with the assumption of non-contextuality. Andrew M. Gleason first proved the theorem in 1957, answering a question posed by George W. Mackey, an accomplishment that was historically significant for the role it played in showing that wide classes of hidden-variable theories are inconsistent with quantum physics. Multiple variations have been proven in the years since. Gleason's theorem is of particular importance for the field of quantum logic and its attempt to find a minimal set of mathematical axioms for quantum theory. Statement of the theorem Conceptual background In quantum mechanics, each physical system is associated with a Hilbert space. For the purposes of this overview, the Hilbert space is assumed to be finite-dimensional. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EPR Paradox
EPR may refer to: Science and technology * EPR (nuclear reactor), European Pressurised-Water Reactor * EPR paradox (Einstein–Podolsky–Rosen paradox), in physics * Earth potential rise, in electrical engineering * East Pacific Rise, a mid-oceanic ridge * Electron paramagnetic resonance * Engine pressure ratio, of a jet engine * Ethylene propylene rubber * Yevpatoria RT-70 radio telescope (Evpatoria planetary radar) * Bernays–Schönfinkel class or effectively propositional, in mathematical logic * WS-Addressing#Endpoint references, Endpoint references in Web addressing * Ethnic Power Relations, dataset of ethnic groups * ePrivacy Regulation (ePR), proposal for the regulation of various privacy-related topics, mostly in relation to electronic communications within the European Union Medicine * Enhanced permeability and retention effect, a controversial concept in cancer research * Emergency Preservation and Resuscitation, a medical procedure * Electronic patient record Environ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marek Żukowski
Marek Żukowski (born 11 December 1952) is a Polish theoretical physicist and lecturer at the University of Gdańsk. He specializes in quantum mechanics, his area of interest in particular concerns the Bell's theorem and quantum interferometry. Life and career He was born on 11 December 1952, in Gdynia, Polish People's Republic. He is a graduate of the Faculty of Mathematics, Physics and Chemistry of the University of Gdańsk. After meeting Anton Zeilinger, he developed an interest in information theory and quantum interferometry. Their first joint scientific paper was published in 1991, later they created a series of international projects called ''Quantum Optics and Quantum Information''. Żukowski also collaborates with Harald Weinfurter from Munich, Jian-Wei Pan from Hefei and Mohamed Bourenanne from Stockholm, as well as the National University of Singapore. He is also involved in a number of European projects such as SCALA and Qubit Applications. He has been working at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anton Zeilinger
Anton Zeilinger (; born 20 May 1945) is an Austrian quantum physicist and Nobel laureate in physics of 2022. Zeilinger is professor of physics emeritus at the University of Vienna and senior scientist at the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences. Most of his research concerns the fundamental aspects and applications of quantum entanglement. In 2007, Zeilinger received the first Inaugural Isaac Newton Medal of the Institute of Physics, London, for "his pioneering conceptual and experimental contributions to the foundations of quantum physics, which have become the cornerstone for the rapidly-evolving field of quantum information". In October 2022, he received the Nobel Prize in Physics, jointly with Alain Aspect and John Clauser for their work involving experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science. Early life and education Anton Zeilinger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard D
Richard is a male given name. It originates, via Old French, from Old Frankish and is a compound of the words descending from Proto-Germanic language">Proto-Germanic ''*rīk-'' 'ruler, leader, king' and ''*hardu-'' 'strong, brave, hardy', and it therefore means 'strong in rule'. Nicknames include "Richie", " Dick", " Dickon", " Dickie", " Rich", " Rick", "Rico (name), Rico", " Ricky", and more. Richard is a common English (the name was introduced into England by the Normans), German and French male name. It's also used in many more languages, particularly Germanic, such as Norwegian, Danish, Swedish, Icelandic, and Dutch, as well as other languages including Irish, Scottish, Welsh and Finnish. Richard is cognate with variants of the name in other European languages, such as the Swedish "Rickard", the Portuguese and Spanish "Ricardo" and the Italian "Riccardo" (see comprehensive variant list below). People named Richard Multiple people with the same name * Richard Anders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POVM
In functional analysis and quantum information science, a positive operator-valued measure (POVM) is a measure whose values are positive semi-definite operators on a Hilbert space. POVMs are a generalization of projection-valued measures (PVM) and, correspondingly, quantum measurements described by POVMs are a generalization of quantum measurement described by PVMs (called projective measurements). In rough analogy, a POVM is to a PVM what a mixed state is to a pure state. Mixed states are needed to specify the state of a subsystem of a larger system (see purification of quantum state); analogously, POVMs are necessary to describe the effect on a subsystem of a projective measurement performed on a larger system. POVMs are the most general kind of measurement in quantum mechanics, and can also be used in quantum field theory. They are extensively used in the field of quantum information. Definition Let \mathcal denote a Hilbert space and (X, M) a measurable space with M a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinhard F
Reinhard is a German, Austrian, Danish, and to a lesser extent Norwegian and Swedish surname (from Germanic ''ragin'', counsel, and ''hart'', strong), and a spelling variant of Reinhardt. Persons with the given name * Reinhard of Blankenburg (after 1107 – 1123), German bishop * Reinhard Böhler (1945–1995), German sidecarcross racer *Reinhard Bonnke (1940–2019), German evangelist * Rainhard Fendrich (born 1955), Austrian singer-songwriter *Reinhard Gehlen (1902–1979), German spymaster * Reinhard Genzel (born 1952), German astrophysicist and Nobel Prize winner *Reinhard Heydrich (1904–1942), German Nazi leader * Reinhard Maack (1892–1969), German explorer * Reinhard Mey (born 1942), German singer *Reinhard Mohn (1921–2009), German media tycoon * Reinhard Odendaal (born 1980), South African award-winning winemaker *Reinhard Scheer (1863–1928), German admiral *Reinhard Selten (1930–2016), German economist *Reinhard Strohm (born 1942), German musicologist * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Werner State
A Werner state is a -dimensional bipartite quantum state density matrix that is invariant under all unitary operators of the form U \otimes U. That is, it is a bipartite quantum state \rho_ that satisfies :\rho_ = (U \otimes U) \rho_ (U^\dagger \otimes U^\dagger) for all unitary operators ''U'' acting on ''d''-dimensional Hilbert space. These states were first developed by Reinhard F. Werner in 1989. General definition Every Werner state W_^ is a mixture of projectors onto the symmetric and antisymmetric subspaces, with the relative weight p \in ,1/math> being the main parameter that defines the state, in addition to the dimension d \geq 2: :W_^ = p \frac P^\text_ + (1-p) \frac P^\text_, where :P^\text_ = \frac(I_+F_), :P^\text_ = \frac(I_-F_), are the projectors and :F_ = \sum_ , i\rangle \langle j, _A \otimes , j\rangle \langle i, _B is the permutation or flip operator that exchanges the two subsystems ''A'' and ''B''. Werner states are separable for ''p'' ≥ and entang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review A
''Physical Review A'' (also known as PRA) is a monthly peer-reviewed scientific journal published by the American Physical Society covering atomic, molecular, and optical physics and quantum information. the editor was Jan M. Rost ( Max Planck Institute for the Physics of Complex Systems). History In 1893, the '' Physical Review'' was established at Cornell University. It was taken over by the American Physical Society (formed in 1899) in 1913. In 1970, ''Physical Review'' was subdivided into ''Physical Review A'', ''B'', ''C'', and ''D''. At that time, section ''A'' was subtitled ''Physical Review A: General Physics''. In 1990, a process was started to split this journal into two, resulting in the creation of '' Physical Review E'' in 1993. Hence, in 1993, ''Physical Review A'' changed its statement of scope to ''Atomic, Molecular and Optical Physics.'' In January 2007, the section of ''Physical Review E'' that published papers on classical optics was merged into ''Physical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measurement In Quantum Mechanics
In quantum physics, a measurement is the testing or manipulation of a physical system to yield a numerical result. A fundamental feature of quantum theory is that the predictions it makes are probabilistic. The procedure for finding a probability involves combining a quantum state, which mathematically describes a quantum system, with a mathematical representation of the measurement to be performed on that system. The formula for this calculation is known as the Born rule. For example, a quantum particle like an electron can be described by a quantum state that associates to each point in space a complex number called a probability amplitude. Applying the Born rule to these amplitudes gives the probabilities that the electron will be found in one region or another when an experiment is performed to locate it. This is the best the theory can do; it cannot say for certain where the electron will be found. The same quantum state can also be used to make a prediction of how the electro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
