Showing papers on "Quantum computer published in 1990"
TL;DR: In this article, a simple, accurate, and fast algorithm for solving the one-dimensional time-independent Schrodinger equation is presented, based on the transfer matrix method, which makes it possible to calculate all bound and quasi-bound energy levels and the corresponding wave functions for an arbitrarily shaped potential profile.
Abstract: A simple, accurate, and fast algorithm for solving the one-dimensional time-independent Schrodinger equation is presented. The algorithm is based on the transfer matrix method. This makes it possible to calculate all bound and quasi-bound energy levels and the corresponding wave functions for an arbitrarily shaped potential profile. The results of calculations are compared with those obtained by other authors for various types of problems. A central part of this study deals with solving the Schrodinger equation in quantum-well structures. The results show that the transfer matrix method is as accurate as other methods, but it is easier to implement and, hence, is superior for calculations on small computer, such as a PC. >
205 citations
TL;DR: In this article, it was shown that the laser model process converges weakly in the sense of the matrix elements to a quantum diffusion whose equation is explicitly obtained, in the same sense as the Heisenberg evolution of an observable of the system to the solution of a quantum Langevin equation.
Abstract: We show that, in the weak coupling limit, the laser model process converges weakly in the sense of the matrix elements to a quantum diffusion whose equation is explicitly obtained. We prove convergence, in the same sense, of the Heisenberg evolution of an observable of the system to the solution of a quantum Langevin equation. As a corollary of this result, via the quantum Feynman-Kac technique, one can recover previous results on the quantum master equation for reduced evolutions of open systems. When applied to some particular model (e.g. the free Boson gas) our results allow to interpret the Lamb shift as an Ito correction term and to express the pumping rates in terms of quantities related to the original Hamiltonian model.
144 citations
TL;DR: In this paper, the case of non-linearly (W-) extended Virasoro symmetries, related to the algebrasAN,N>1, is considered along the same line.
Abstract: Recently, an infinite family of chiral Virasoro vertex operators, whose exchange algebra is given by the universalR-matrix ofSL(2) q , has been constructed. In the present paper, the case of non-linearly (W-) extended Virasoro symmetries, related to the algebrasAN,N>1, is considered along the same line. Contrary to the previous case (A1) the standardR-matrix ofSL(N+1)q does not come out, and a different solution of Yang and Baxter's equations is derived. The associated quantum group structure is displayed.
140 citations
TL;DR: A new definition of computability is proposed which lays the foundations for a theory of cybernetic and intelligent machines in which the classical limits imposed by discrete algorithmic procedures are offset by the use of continuous operators on unlimited data.
Abstract: Many attempts1, 7, 8, 35 have been made to overcome the limit imposed by the Turing Machine34 to realise general mathematical functions and models of (physical) phenomena. They center around the notion of computability. In this paper we propose a new definition of computability which lays the foundations for a theory of cybernetic and intelligent machines in which the classical limits imposed by discrete algorithmic procedures are offset by the use of continuous operators on unlimited data. This data is supplied to the machine in a totally parallel mode, as a field or wave. This theory of machines draws its concepts from category theory, Lie algebras, and general systems theory. It permits the incorporation of intelligent control into the design of the machine as a virtual element. The incorporated control can be realized in many (machine) configurations of which we give three: a) a quantum mechanical realization appropriate to a possible understanding of the quantum computer and other models of the physi...
19 citations
NEC1
TL;DR: The authors propose organic quantum computing system models based on novel organic quantum dots device architectures and multiple valued cellular automata dynamics and the MOSFET vertica.1 quantum device architecture.
Abstract: The authors propose organic quantum computing system models. The systems are based on novel organic quantum dots device architectures and multiple valued cellular automata( CA ) dynamics. In the systems, the MOSFET vertica.1 quantum device architecture is considered. which is composed of massively paralleled quantum dots structure applying organic molecular crystal superlattices multiple layers and inherent tunneling modes.
5 citations
4 citations
Book•
01 Jan 1990
TL;DR: In this article, a quantum stochastic calculus in fock space of input and output non-emolition processes is presented. But it is not a quantum conditional probability space.
Abstract: Quantum Langevin equation in the weak coupling limit.- On the low density limit of Boson models.- Quantum stochastic flows and non abelian cohomology.- Quantum diffusions on involutive algebras.- Some Markov semigroups in quantum probability.- A quantum stochastic calculus in fock space of input and output nondemolition processes.- Stochastic transitions on preduals of von Neumann algebras.- Quantum stochastic calculus and a boson Levy theorem.- Locally independent boson systems.- Time-inhomogeneous and nonlinear quantum evolutions.- Quantum poisson processes: Physical motivations and applications.- Quantum central limit and coarse graining.- An open problem in quantum shot noise.- A method of operator estimation and a strong law of large numbers in von Neumann algkbras.- An analog of the Ito decomposition for multiplicative processes with values in a Lie group.- Stochastic dilations of quantum dynamical semigroups using one-dimensional quantum stochastic calculus.- Sluggish decay of preparation effects in low temperature quantum systems.- Almost sure convergence of iterates of contractions in noncommutative L2-spaces.- Duality transform as *-algebraic isomorphism.- Rigidity of the poisson convolution.- A discrete entropic uncertainty relation.- Working with Quantum Markov States and their classical analogues.- Dynamical entropy, quantum K-systems and clustering.- A continuous time version of Stinespring's theorem on completely positive maps.- The topology of the convergence in probability in a W*-algebra is normal.- First steps towards a Donsker and Varadhan theory in operator algebras.- Quantum conditional probability spaces.- Quantum diffusions on the rotation algebras and the quantum hall effect.- Quantum dirichlet forms, differential calculus and semigroups.- Gaussian states on bialgebras.- Quantum macrostatistics and irreversible thermodynamics.- Correction to the hydrodynamical approximation for groups of Bogoljubov transformations.- Bell's inequalities and quantum field theory.
3 citations
01 Jan 1990
TL;DR: In this article, the notion of probabilistic time was introduced as a way to obtain Quantum Field Theory in curved space-time from Quantum Gravity and the problem of the arrow of time was studied.
Abstract: The notion of “Probabilistic Time” is studied as a way to obtain Quantum Field Theory in curved space-time from Quantum Gravity. It is shown how ideal and real clocks measure the probabilistic time and how the universe can be used a a real clock. The problem of the arrow of time is studied because it is related with the definition of probabilistic time.
2 citations
27 Dec 1990
TL;DR: In this article, the transmission of quantum noise through the basic systems used in optical computing is discussed, including multipliers, linear algebra processors, nonlinear elements, and cascaded systems involving detection and regeneration of light.
Abstract: The transmission of quantum noise through the basic systems used in optical computing is discussed. Multipliers, linear algebra processors, nonlinear elements, and cascaded systems involving detection and regeneration of light are examined.
08 Apr 1990
TL;DR: A large scale Quantum Monte f2arlo simulation is performed on the Mark IIIfp II.~yercube supercomputer to systematically study tile quantum spin dynamics of the recently discoveretl high-T, superconducting mother material.
Abstract: A large scale Quantum Monte f2arlo simulation is performed on the Mark IIIfp II.~yercube supercomputer to systematically study tile quantum spin dynamics of the recently discoveretl high-T, superconducting mother material. Tlie algorithm is very efficiently implemented on the 1Iy~ ercube. The 3dimensional lattice is partitioned into a ring of processor nodes. Parallelism is also achieved by running several independent simulations on several processor rings simultaneously. The local updates are easily handled by the CROS communication system. Global updates are efficiently implemented by a “gather - scatter” routines written in CROS calls. Spins are packed into 32-bit words along the time direction. Local updates are vectoi ized along time direction. We also report a systeinatic performance analysis. The efficiency of the iinplei,ieiitation is over 90%. dimensional magnetism. Magnetic properties are believed to play significant role in the new mechanism for the high-T, superconductivity. These magnetism is essentially modeled by the quantum antiferromagnetic Heisenberg model: H = J C(Si”Sj” + si”si” + SfSjt) (U)