DEUTSCH D. (1985). 'Quantum theory, the Church-Turing principle and the universal quantum computer', Proc. R. Soc. Lond. A400 97-117.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....SPEC, a description of a machine, and on the other we have the entity e. How do we bridge the gap and say that e is such a machine (at the time in question) The bridge is effected by means of a system of labelling for e. The concept of a labelling of a device is also used by Gandy 1980 and 7 Deutsch 1985. For example, labels may be eight binary digits long and be associated with groupings of subdevices in the following way: the possible states measured in volts, say of these subdevices are divided into two mutually exclusive classes and a state is labelled 0 if it falls into the first, 1 ....

Deutsch, D. 1985. 'Quantum Theory, the Church-Turing Principle and the Universal Quantum Computer'. Proceedings of the Royal Society, Series A, vol.400, pp.97-117.

....for the question Are there mechanical procedures that are not mechanical appears self answering. A further reason to revise traditional terminology in the manner suggested here is provided by the recent emergence of the field of quantum computation. Algorithms for quantum Turing machines (Deutsch 1985, Solovay and Yao 1996) are not effective procedures, since not all the primitive operations of a quantum Turing machine can be performed by a person unaided by machinery. While the algorithms executed by Deutsch Solovay Yao quantum Turing machines are not effective procedures, they are ....

Deutsch, D. 1985. 'Quantum Theory, the Church-Turing Principle and the Universal Quantum Computer'. Proceedings of the Royal Society, Series A, 400, pp.97-117.

....is the most general possible classical computer, and all general purpose computers are approximations to it. U can simulate any Turing machine with perfect precision, where a TM in turn is a theoretical model that can simulate the execution of a single algorithm on a classical computer. Deutsch [Deutsch, 1985] showed that a universal quantum computer Q can perfectly simulate any TM and can also simulate any quantum computer or simulator with arbitrary precision. Quantum computers cannot compute a function that is not Turing computable, but they do give new methods of computation for many classes of ....

....networks which is a generalisation of the theory of quantum logic gates is also described [Deutsch, 1989] thereby grounding such networks in future developments in nanotechnology, where the operation of nano devices will be best (and perhaps only) described at the quantum level. Deutsch [Deutsch, 1985, Deutsch, 1989] also showed that any physical process could be modelled perfectly on a quantum computer, and that such a computer would be able to perform tasks more quickly than traditional machines. This, he argued, was because the quantum machines would be able to exploit 1 Nano = 10 ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proceedings of the Royal Society of London, A400:97--111.

....see, e.g. 44] 42] 6] and [21] If we regard visual perception as paradigmatic, it is reasonable to adopt a 2 dimensional (i.e. complex) model. Such a viewpoint would be compatable with optical implementation, and would also be required for a neural net based on quantum computation [14], 43] Earlier, we considered the application of neural networks to pictures. While L p norms are commonly used in the current theory of neural network approximation, for the space X of pictures or interesting subspaces which are naturally occurring within some given context, one may question the ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proc. Royal Soc. London, A 400, 97-117.

....This move down in scale takes us from systems that can be understood (to a good enough approximation) using classical mechanics alone, to those which require a quantum mechanical understanding. Thus, it should not be surprising to find that the idea of quantum computation is not new (see, e.g. [Deutsch, 1985] and [Feynman, 1982] However, most if not all work so far has been understandably speculative. This paper continues in this speculative vein, but tries to be concrete in describing what an implementation of a quantum computational system might be like. There are two ways in which the focus here ....

....x i , each weighted by some complex scalar ff i . Under certain conditions, this quantum state decoheres, and the particle adopts one of the x i as its determinate state, with a probability that is determined by the ratios of the ff i . The idea proposed in [Feynman, 1982] and developed in, e.g. [Deutsch, 1985], is that if such superpositional states were used to implement the states of a computer, then various registers or memory locations in the computer would not be conventional bits with a determinate value of 1 or 0, but would instead be quantum bits qubits which are superpositions of both ....

[Article contains additional citation context not shown here]

Deutsch, D. (1985). Quantum theory, the church-turing principle and the universal quantum computer. Proceedings of the Royal Society of London A, 400:97--117.

....than one interacting particles be simulated. Alternatively, one can demonstrate the universality of our evolution equation simply by noting that there exists a G such that that equation emulates Schrodinger s equation, and by then appealing directly to the field of quantum Turing machine theory (Deutsch, 1985). Such arguments appealing to quantum mechanics do not apply if one is interested in real valued field computers of course. And even if one allows complex valued fields, such arguments are not particularly insightful or useful, especially if one is interested real valued field computers andin ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proceedings of the Royal Society of London A, 400, 97--117.

.... The problem is that each level, to lend credence to its claim for accounting for mind brain, posits a form of computation and representation not just appropriate for that level but also necessary 12 Interestingly, Hameroff and Penrose have opposite views on the adequacy of quantum computing (Deutsch, 1985, 1992) for accounting for quantum mechanical effects, with Hameroff seeing no reason in principle why quantum computing should not provide adequate computational accounts of quantum behaviour and coherence within microtubules, and Penrose believing that quantum computing, because it is still ....

....in terms of layered networks will not be accurate. What is needed is a clearer understanding of the internal workings of neurons in biomolecular terms. Physical scientists may argue that biomolecular computing is still at too high a level and that its own computational arm, quantum computing (e.g. Deutsch, 1985, 1992; Menneer and Narayanan, 1995) provides a more appropriate computational level. A radical physical scientist may also claim that consciousness thought is a feature of the brain s physical actions where these physical actions cannot even be adequately expressed in any computational terms ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer, Proceedings of the Royal Society (London), A400, 97--117.

....Schrodinger s equation for a set of more than one interacting particles be simulated. Alternatively, one can demonstrate the universality of our evolution equation by noting that there exists a Schrodinger s equation G, and by then appealing directly to the field of quantum Turning machine theory (Deutsch, 1985). This argument is not particularly insightful or useful however, especially if one is interested in field computers as possible models of the human brain. To put it mildly, there are many poorly understood steps in extrapolating upwards from quantum mechanics to macroscopic human brains. 3.2 ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proceedings of the Royal Society of London A, 400, 97--117.

....learn faster than the controls and give an equal number of errors, or less, in testing. 1 Introduction Interest in quantum computing (QC) physically based computation founded on quantum theoretic concepts has grown recently in the computer and cognitive sciences as a result of claims by Deutsch (1985, 1989) and Shor (1994) that problems regarded by computer scientists as NP hard or NP complete can be solved by a quantum computer. Since it is regarded that if a computational solution can be found to one of the problems in the NP complete class then a solution can be found to all problems in ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proceedings of the Royal Society of London, A400, 97--117.

....is the most general possible classical computer, and all general purpose computers are approximations to it. U can simulate any Turing machine with perfect precision, where a TM in turn is a theoretical model that can simulate the execution of a single algorithm on a classical computer. Deutsch [Deutsch, 1985] showed that a universal quantum computer Q can perfectly simulate any TM and can also simulate any quantum computer or simulator with arbitrary precision. Quantum computers cannot compute a function that is not Turing computable, but they do give new methods of computation for many classes of ....

....networks which is a generalisation of the theory of quantum logic gates is also described [Deutsch, 1989] thereby grounding such networks in future developments in nanotechnology, where the operation of nano devices will be best (and perhaps only) described at the quantum level. Deutsch [Deutsch, 1985, Deutsch, 1989] also showed that any physical process could be modelled perfectly on a quantum computer, and that such a computer would be able to perform tasks more quickly than traditional machines. This, he argued, was because the quantum machines would be able to exploit the phenomenon of ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proceedings of the Royal Society of London, A400:97--111.

....why some straightforward attempts to exploit these capabilities for search are not particularly effective, then motivates and describes a new search algorithm. 3. 1 An Overview of Quantum Computers The basic distinguishing feature of a quantum computer (Benioff, 1982; Bernstein Vazirani, 1993; Deutsch, 1985, 1989; Ekert Jozsa, 1995; Feynman, 1986; Jozsa, 1992; Kimber, 1992; Lloyd, 1993; Shor, 1994; Svozil, 1995) is its ability to operate simultaneously on a collection of classical states, thus potentially performing many operations in the time a classical computer would do just one. Alternatively, ....

Deutsch, D. (1985). Quantum theory, the Church-Turing principle and the universal quantum computer. Proc. R. Soc. London A, 400, 97--117.

....of classical probabilistic computation and quantum computation which we will employ in this paper. Those who are already familiar with quantum models of computation can skip the rest of this section. Our development is based on Turing machines, but can just as easily be based on quantum circuits [Deu85], which are polynomially equivalent to quantum Turing machines [Yao93] See the references for more details regarding the models used here (e.g. Sim94] as well as equivalent formulations (e.g. Ber97] A classical probabilistic computation can be viewed as a tree. Each node in the tree is ....

.... dot product of the bit vectors y and y 0 [DJ92, Sim94] Thus Q scanning the first m bits of the tape t corresponds to the global transition jx; 0; 0i 7 1 2 m=2 X y jx; y; 0i: Q then simulates the deterministic computation of L(x; y) in a reversible manner, using other work tapes [Deu85, Ben82]. 1 Let b y be the one bit result of the 1 This computation is also done obliviously so that the internal state and tape head position of the machine is the same for all components of the superposition at any given time. If we used quantum circuits for the proof, this technicality goes ....

D. Deutsch. Quantum theory. In Proceedings of the Royal Society of London, pages 97--117, 1985.

No context found.

DEUTSCH D. (1985). 'Quantum theory, the Church-Turing principle and the universal quantum computer', Proc. R. Soc. Lond. A400 97-117.

No context found.

D. Deutsch. Quantum theory. In Proceedings of the Royal Society of London, pages 97--117, 1985.

No context found.

Deutsch, D (1985), Quantum theory, the ChurchTuring principle and the universal quantum computer, Proc. R. Soc, Lond. A 400, pp. 97-117.

No context found.

Deutsch D., (1985), Quantum theory, the Church-Turing principle and the universal quantum computer, Proc. Roy. Soc. Lond. A400, 97-117.

No context found.

Deutsch, D. (1985). Quantum theory, the church-turing principle and the universal quantum computer. Proceedings of the Royal Society of London A, 400:97--117.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC