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Timeline Of Quantum Computing
This is a timeline of quantum computing. 1960s 1968 * Stephen Wiesner invents conjugate coding. (published in ACM SIGACT News 15(1):78–88) 1970s 1970 * James Park articulates the no-cloning theorem. 1973 * Alexander Holevo publishes a paper showing that ''n'' qubits can carry more than ''n'' classical bits of information, but at most ''n'' classical bits are accessible (a result known as "Holevo's theorem" or "Holevo's bound"). * Charles H. Bennett shows that computation can be done reversibly. 1975 * R. P. Poplavskii publishes "Thermodynamical models of information processing" (in Russian) which showed the computational infeasibility of simulating quantum systems on classical computers, due to the superposition principle. 1976 * Polish mathematical physicist Roman Stanisław Ingarden publishes the paper "Quantum Information Theory" in Reports on Mathematical Physics, vol. 10, 43–72, 1976. (The paper was submitted in 1975.) It is one of the first a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Computing
Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computations are known as quantum computers. Though current quantum computers may be too small to outperform usual (classical) computers for practical applications, larger realizations are believed to be capable of solving certain computational problems, such as integer factorization (which underlies RSA encryption), substantially faster than classical computers. The study of quantum computing is a subfield of quantum information science. There are several models of quantum computation with the most widely used being quantum circuits. Other models include the quantum Turing machine, quantum annealing, and adiabatic quantum computation. Most models are based on the quantum bit, or " qubit", which is somewhat analogous to the bit in classical computation. A qubit can be in a 1 or 0 quan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turing Machines
A Turing machine is a mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules. Despite the model's simplicity, it is capable of implementing any computer algorithm. The machine operates on an infinite memory tape divided into discrete cells, each of which can hold a single symbol drawn from a finite set of symbols called the alphabet of the machine. It has a "head" that, at any point in the machine's operation, is positioned over one of these cells, and a "state" selected from a finite set of states. At each step of its operation, the head reads the symbol in its cell. Then, based on the symbol and the machine's own present state, the machine writes a symbol into the same cell, and moves the head one step to the left or the right, or halts the computation. The choice of which replacement symbol to write and which direction to move is based on a finite table that specifies what to do for each co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Quantum Computer
A quantum Turing machine (QTM) or universal quantum computer is an abstract machine used to model the effects of a quantum computer. It provides a simple model that captures all of the power of quantum computation—that is, any quantum algorithm can be expressed formally as a particular quantum Turing machine. However, the computationally equivalent quantum circuit is a more common model. Quantum Turing machines can be related to classical and probabilistic Turing machines in a framework based on transition matrices. That is, a matrix can be specified whose product with the matrix representing a classical or probabilistic machine provides the quantum probability matrix representing the quantum machine. This was shown by Lance Fortnow. Informal sketch A way of understanding the quantum Turing machine (QTM) is that it generalizes the classical Turing machine (TM) in the same way that the quantum finite automaton (QFA) generalizes the deterministic finite automaton (DFA). In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Deutsch
David Elieser Deutsch ( ; born 18 May 1953) is a British physicist at the University of Oxford. He is a Visiting Professor in the Department of Atomic and Laser Physics at the Centre for Quantum Computation (CQC) in the Clarendon Laboratory of the University of Oxford. He pioneered the field of quantum computation by formulating a description for a quantum Turing machine, as well as specifying an algorithm designed to run on a quantum computer. He has also proposed the use of entangled states and Bell's theorem for quantum key distribution and is a proponent of the many-worlds interpretation of quantum mechanics. Early life and education Deutsch was born into a Jewish family in Haifa, Israel on 18 May 1953, the son of Oskar and Tikva Deutsch. In London, David attended Geneva House school in Cricklewood (his parents owned and ran the Alma restaurant on Cricklewood Broadway), followed by William Ellis School in Highgate (then a voluntary aided school in north London) before readi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilles Brassard
Gilles Brassard, is a faculty member of the Université de Montréal, where he has been a Full Professor since 1988 and Canada Research Chair since 2001. Education and early life Brassard received a Ph.D. in Computer Science from Cornell University in 1979, working in the field of cryptography with John Hopcroft as his advisor. Research Brassard is best known for his fundamental work in quantum cryptography, quantum teleportation, quantum entanglement distillation, quantum pseudo-telepathy, and the classical simulation of quantum entanglement.Herzberg runner-up: Gilles Brassard Natural Sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennis Dieks
Dennis Geert Bernardus Johan Dieks (born 1 June 1949, in Amsterdam) is a Dutch physicist and philosopher of physics. Work In 1982 he proved the no-cloning theorem (independently discovered in the same year by William Wootters and Wojciech H. Zurek). In 1989 he proposed a new interpretation of quantum mechanics, later known as a version of the modal interpretation of quantum mechanics. He also worked on the philosophy of space and time, the logic of probabilistic reasoning, and the theory of explanation. Dieks is a professor at Utrecht University and a member of the Royal Netherlands Academy of Arts and Sciences since 2008. He is co-editor of the journal ''Studies in History and Philosophy of Modern Physics'', an editor of the journal ''Foundations of Physics'' (Editor-in-chief C. Rovelli) and co-editor of the book series ''European Studies in Philosophy of Science'' (Springer). Dieks was also an able chess player, reaching a maximum Elo rating of 2290 in 1974 and even beatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wojciech Zurek
Wojciech Hubert Zurek ( pl, Żurek; born 1951) is a theoretical physicist and a leading authority on quantum theory, especially decoherence and non-equilibrium dynamics of symmetry breaking and resulting defect generation (known as the Kibble–Zurek mechanism). Education He attended the I Liceum Ogólnokształcące im. Mikołaja Kopernika (1st Secondary High School of Mikołaj Kopernik) in Bielsko-Biała. Zurek earned his M.Sc. in physics at AGH University of Science and Technology, Kraków, Poland in 1974 and completed his Ph.D. under advisor William C. Schieve at the University of Texas at Austin in 1979. He spent two years at Caltech as a Tolman Fellow, and started at LANL as a J. Oppenheimer Fellow. Career He was the leader of the Theoretical Astrophysics Group at Los Alamos from 1991 until he was made a Laboratory Fellow in the Theory Division in 1996. Zurek is currently a foreign associate of the ''Cosmology'''' Program'' at the Canadian Institute for Advanced Resear ... [...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 advis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Feynman
Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfluidity of supercooled liquid helium, as well as his work in particle physics for which he proposed the parton model. For contributions to the development of quantum electrodynamics, Feynman received the Nobel Prize in Physics in 1965 jointly with Julian Schwinger and Shin'ichirō Tomonaga. Feynman developed a widely used pictorial representation scheme for the mathematical expressions describing the behavior of subatomic particles, which later became known as Feynman diagrams. During his lifetime, Feynman became one of the best-known scientists in the world. In a 1999 poll of 130 leading physicists worldwide by the British journal '' Physics World'', he was ranked the seventh-greatest physicist of all time. He assisted in the develop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Completeness
In logic, a functionally complete set of logical connectives or Boolean operators is one which can be used to express all possible truth tables by combining members of the set into a Boolean expression.. ("Complete set of logical connectives").. (" nctional completeness of set of logical operators"). A well-known complete set of connectives is . Each of the singleton sets and is functionally complete. A gate or set of gates which is functionally complete can also be called a universal gate / gates. A functionally complete set of gates may utilise or generate 'garbage bits' as part of its computation which are either not part of the input or not part of the output to the system. In a context of propositional logic, functionally complete sets of connectives are also called (expressively) adequate.. (Defines "expressively adequate", shortened to "adequate set of connectives" in a section heading.) From the point of view of digital electronics, functional completeness means tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancilla Bit
Ancilla bits are some extra bits being used to achieve some specific goals in computation (e.g. reversible computation). In classical computation, any memory bit can be turned on or off at will, requiring no prior knowledge or extra complexity. However, this is not the case in quantum computing or classical reversible computing. In these models of computing, all operations on computer memory must be reversible, and toggling a bit on or off would lose the information about the initial value of that bit. For this reason, in a quantum algorithm there is no way to deterministically put bits in a specific prescribed state unless one is given access to bits whose original state is known in advance. Such bits, whose values are known ''a priori'', are known as ancilla bits in a quantum or reversible computing task. A trivial use for ancilla bits is downgrading complicated quantum gates into simple gates. For example, by placing controls on ancilla bits, a Toffoli gate can be u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Van Leeuwen
Jan van Leeuwen (born December 17, 1946, in Waddinxveen) is a Dutch computer scientist and Emeritus professor of computer science at the Department of Information and Computing Sciences at Utrecht University.Curriculum vitae retrieved 2011-03-27. Education and career Van Leeuwen completed his undergraduate studies in mathematics at in 1967 and received a PhD in mathematics in 1972 from the same institution under the supervision of Dirk van Dalen.. After postdoctoral studies at the |
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