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Weak Value
In quantum mechanics (and computation), a weak value is a quantity related to a shift of a measuring device's pointer when usually there is pre- and postselection. It should not be confused with a weak measurement, which is often defined in conjunction. The weak value was first defined by Yakir Aharonov, David Albert, and Lev Vaidman, published in Physical Review Letters 1988, and is related to the two-state vector formalism. There is also a way to obtain weak values without postselection. Definition and Derivation There are many excellent review articles on weak values (see e.g. ) here we briefly cover the basics. Definition We will denote the initial state of a system as , \psi_i\rangle, while the final state of the system is denoted as , \psi_f\rangle. We will refer to the initial and final states of the system as the pre- and post-selected quantum mechanical states. With respect to these states, the ''weak value'' of the observable A is defined as: A_w = \frac. Notice that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is the foundation of all quantum physics, which includes quantum chemistry, quantum field theory, quantum technology, and quantum information science. Quantum mechanics can describe many systems that classical physics cannot. Classical physics can describe many aspects of nature at an ordinary (macroscopic and Microscopic scale, (optical) microscopic) scale, but is not sufficient for describing them at very small submicroscopic (atomic and subatomic) scales. Classical mechanics can be derived from quantum mechanics as an approximation that is valid at ordinary scales. Quantum systems have Bound state, bound states that are Quantization (physics), quantized to Discrete mathematics, discrete values of energy, momentum, angular momentum, and ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discover (magazine)
''Discover'' is an American general audience science magazine launched in October 1980 by Time Inc. It is currently owned by LabX Media Group. History Founding ''Discover'' was created primarily through the efforts of ''Time'' magazine editor Leon Jaroff. He noticed that magazine sales jumped every time the cover featured a science topic. Jaroff interpreted this as a considerable public interest in science, and in 1971, he began agitating for the creation of a science-oriented magazine. This was difficult, as a former colleague noted, because "Selling science to people who graduated to be managers was very difficult".Hevesi, Dennis"Leon Jaroff, Editor at Time and Discover Magazines, Dies at 85" ''The New York Times'', 21 October 2012 Jaroff's persistence finally paid off, and ''Discover'' magazine published its first edition in 1980. ''Discover'' was originally launched into a burgeoning market for science magazines aimed at educated non-professionals, intended to be eas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles H
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "free man". The Old English descendant of this word was '' Ċearl'' or ''Ċeorl'', as the name of King Cearl of Mercia, that disappeared after the Norman conquest of England. The name was notably borne by Charlemagne (Charles the Great), and was at the time Latinized as ''Karolus'' (as in ''Vita Karoli Magni''), later also as '' Carolus''. Etymology The name's etymology is a Common Germanic noun ''*karilaz'' meaning "free man", which survives in English as churl (James (wikt:Appendix:Proto-Indo-European/ǵerh₂-">ĝer-, where the ĝ is a palatal consonant, meaning "to rub; to be old; grain." An old man has been worn away and is now grey with age. In some Slavic languages, the name ''Drago (given name), Drago'' (and variants: ''Drago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Mermin
Nathaniel David Mermin (; born 30 March 1935) is a solid-state physicist at Cornell University best known for the eponymous Hohenberg–Mermin–Wagner theorem, his application of the term " boojum" to superfluidity, his textbook with Neil Ashcroft on solid-state physics, and for contributions to the foundations of quantum mechanics and quantum information science. Education and career Mermin was born in 1935 in New Haven, Connecticut. He obtained a bachelor's degree in mathematics from Harvard University in 1956, graduating ''summa cum laude.'' He remained at Harvard for his graduate studies, earning a PhD in physics in 1961. After holding postdoctoral positions at the University of Birmingham and the University of California, San Diego, he joined the Cornell University faculty in 1964. He became a Cornell professor emeritus in 2006. Early in his career, Mermin worked in statistical physics and condensed-matter physics, including the study of matter at low temperatures, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthony James Leggett
Sir Anthony James Leggett (born 26 March 1938) is a British–American theoretical physicist and professor emeritus at the University of Illinois Urbana-Champaign (UIUC). Leggett is widely recognised as a world leader in the theory of low-temperature physics, and his pioneering work on superfluidity was recognised by the 2003 Nobel Prize in Physics. He has shaped the theoretical understanding of normal and superfluid helium liquids and strongly coupled superfluids. He set directions for research in the quantum physics of macroscopic dissipative systems and use of condensed systems to test the foundations of quantum mechanics. Early life and education Leggett was born in Camberwell, South London, and raised Catholic. His father's forebears were village cobblers in a small village in Hampshire; Leggett's grandfather broke with this tradition to become a greengrocer; his father would relate how he used to ride with him to buy vegetables at the Covent Garden market in London. His m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asher Peres
Asher Peres (; January 30, 1934 – January 1, 2005) was an Israeli physicist. Peres is best known for his work relating quantum mechanics and information theory. He helped to develop the Peres–Horodecki criterion for quantum entanglement, as well as the concept of quantum teleportation, and collaborated with others on quantum information and special relativity. He also introduced the Peres metric and researched the Hamilton–Jacobi–Einstein equation in general relativity. With Mario Feingold, he published work in quantum chaos that is known to mathematicians as the Feingold–Peres conjecture and to physicists as the Feingold–Peres theory. Life According to his autobiography, he was born ''Aristide Pressman'' in Beaulieu-sur-Dordogne in France, where his father, a Polish electrical engineer, had found work laying down power lines. He was given the name ''Aristide'' at birth, because the name his parents wanted, ''Asher'', the name of his maternal grandfather, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grover's Algorithm
In quantum computing, Grover's algorithm, also known as the quantum search algorithm, is a quantum algorithm for unstructured search that finds with high probability the unique input to a black box function that produces a particular output value, using just O(\sqrt) evaluations of the function, where N is the size of the function's domain of a function, domain. It was devised by Lov Grover in 1996. The analogous problem in classical computation would have a query complexity O(N) (i.e., the function would have to be evaluated O(N) times: there is no better approach than trying out all input values one after the other, which, on average, takes N/2 steps). Charles H. Bennett (physicist), Charles H. Bennett, Ethan Bernstein, Gilles Brassard, and Umesh Vazirani proved that any quantum solution to the problem needs to evaluate the function \Omega(\sqrt) times, so Grover's algorithm is Asymptotically optimal algorithm, asymptotically optimal. Since classical algorithms for NP-completenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arun K
Arun may refer to: People * Arun (given name) ** Arun (actor), Indian actor * Arun (surname) Places * Arun, Badakhshan, Afghanistan * Arun (England), a region of southeasthern England ** Arun District, West Sussex, England * Arun Banner, an administrative division (banner) of Inner Mongolia, China * Arun, Sumatra, a vassal state, now in Indonesia * Arun gas field, Sumatra, Indonesia * Aran va Bidgol ('Aran and Bidgol'), Isfahan Province, Iran ** Aran va Bidgol County * Arun rural municipality, Nepal * Wat Arun, a temple in Bangkok, Thailand Rivers and canals * Arun River, China–Nepal * River Arun, in West Sussex, England * Wey and Arun Canal, in the south east of England Other uses * Aruṇa, a god in Hinduism * ''Arun''-class lifeboat * , two ships of the Royal Navy * Arun, a fictional character played by Sachin Pilgaonkar in the Indian films ''Ankhiyon Ke Jharokhon Se'' (1978) and '' Jaana Pehchana'' (2011) See also * * * Aaron (other) Aaron is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Broglie–Bohm Theory
The de Broglie–Bohm theory is an interpretation of quantum mechanics which postulates that, in addition to the wavefunction, an actual configuration of particles exists, even when unobserved. The evolution over time of the configuration of all particles is defined by a guiding equation. The evolution of the wave function over time is given by the Schrödinger equation. The theory is named after Louis de Broglie (1892–1987) and David Bohm (1917–1992). The theory is deterministic and explicitly nonlocal: the velocity of any one particle depends on the value of the guiding equation, which depends on the configuration of all the particles under consideration. Measurements are a particular case of quantum processes described by the theory—for which it yields the same quantum predictions as other interpretations of quantum mechanics. The theory does not have a " measurement problem", due to the fact that the particles have a definite configuration at all times. The Born ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partha Ghose
Partha Ghose (born 1939) is an Indian physicist, author, philosopher, musician and former professor at the S.N. Bose National Centre for Basic Sciences in Kolkata. He is the former chairman of Satyajit Ray Film and Television Institute, Kolkata and a member of the board of trustees of the Academy of Fine Arts, Kolkata. Life and works Partha Ghose is one of India's best known popularizers of modern science. He has written influential papers and booksP. Ghose, Testing Quantum Mechanics on New Ground, Cambridge University Press, UK, April 1999." on physics as well as popular books on science.P. Ghose and D. Home, Riddles in Your Tea Cup, Rupa & Co., 1990, Adam Hilger, UK, Sept 1994. The book has been published in several Indian languages, Italian, Japanese and Turkish.P. Ghose, ''Solar Eclipse : The Celestial Diamond'', Harper-Collins of India, 1996. He was an anchorperson in the popular Indian TV shows Quest and Eureka. He has directed plays and appeared in media programmes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double-slit Interferometer
In modern physics, the double-slit experiment demonstrates that light and matter can exhibit behavior of both classical particles and classical waves. This type of experiment was first performed by Thomas Young in 1801, as a demonstration of the wave behavior of visible light. In 1927, Davisson and Germer and, independently, George Paget Thomson and his research student Alexander Reid demonstrated that electrons show the same behavior, which was later extended to atoms and molecules. Thomas Young's experiment with light was part of classical physics long before the development of quantum mechanics and the concept of wave–particle duality. He believed it demonstrated that the Christiaan Huygens' wave theory of light was correct, and his experiment is sometimes referred to as Young's experiment or Young's slits. The experiment belongs to a general class of "double path" experiments, in which a wave is split into two separate waves (the wave is typically made of many photons an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
