1,720,970 research outputs found
Decoherence in Heisenberg's representation
No full textBlanchard P, Olkiewicz R. Decoherence in Heisenberg's representation. INTERNATIONAL JOURNAL OF MODERN PHYSICS B. 2004;18(04n05):501-507.Various physical effects resulting from environmental decoherence are discussed in the algebraic framework. An example of dynamical de-quantization of a quantum particle is considered
Decoherence-induced continuous pointer states
No full textBlanchard P, Olkiewicz R. Decoherence-induced continuous pointer states. PHYSICAL REVIEW LETTERS. 2003;90(1): 10403.We investigate the reduced dynamics in the Markovian approximation of an infinite quantum spin system linearly coupled to a phonon field at positive temperature. The achieved diagonalization leads to a selection of the continuous family of pointer states corresponding to a configuration space of the one-dimensional Ising model. Such a family provides a mathematical description of an apparatus with continuous readings
Interacting quantum and classical continuous systems - II. Asymptotic behavior of the quantum subsystem
No full textBlanchard P, Olkiewicz R. Interacting quantum and classical continuous systems - II. Asymptotic behavior of the quantum subsystem. JOURNAL OF STATISTICAL PHYSICS. 1999;94(5/6):933-953.In the Framework of event-enhanced quantum theory the dynamical equation for the reduced density matrix of a quantum system interacting with a continuous classical system is derived. The asymptotic behavior of the corresponding dynamical semigroup is discussed. The example of a quantum-classical coupling on Lobatchevski space is presented
Interacting quantum and classical continuous systems - I. The piecewise deterministic dynamics
No full textBlanchard P, Olkiewicz R. Interacting quantum and classical continuous systems - I. The piecewise deterministic dynamics. JOURNAL OF STATISTICAL PHYSICS. 1999;94(5/6):913-931.A mathematical construction of a Markov-Feller process associated with a completely positive coupling between classical and quantum systems is proposed. The example of the free classical particle on the Lobatchevski space Q interacting with the quantum system characterized by coherent states on Q is considered
Non-quasi-free dynamical semi-group on CCR algebras
No full textBlanchard P, Hellmich M, Lugiewicz P, Olkiewicz R. Non-quasi-free dynamical semi-group on CCR algebras. BiBoS Preprint. 2010
Decoherence induced transition from quantum to classical dynamics
No full textBlanchard P, Olkiewicz R. Decoherence induced transition from quantum to classical dynamics. REVIEWS IN MATHEMATICAL PHYSICS. 2003;15(03):217-243.Framework for a general discussion of environmentally induced classical properties, like superselection rules, privileged basis and classical behavior, in quantum systems with both finite and infinite number of degrees of freedom is proposed. A number of examples showing that classical properties do not have to be postulated as an independent ingredient are given. In particular, it is shown that infinite open quantum systems in some cases may behave like simple classical dynamical systems
Entangled versus classical quantum states
No full textBlanchard P, Jakobczyk L, Olkiewicz R. Entangled versus classical quantum states. PHYSICS LETTERS A. 2001;280(1-2):7-16.We discuss usefulness of the criterion of fragility with respect to a measurement-like dynamics in the description of entanglement of both purr and statistical states. (C) 2001 Elsevier Science B.V. All rights reserved
Measures of entanglement based on decoherence
No full textBlanchard P, Jakobczyk L, Olkiewicz R. Measures of entanglement based on decoherence. JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL. 2001;34(41):8501-8516.New measures of entanglement-the time of disentanglement and the rate of decoherence-of states of a compound system are proposed. They are based on the dynamical properties of the system induced by the measurement-like interaction with an environment. In particular, it is shown that in the case of two qubits the time of disentanglement may serve as a practical measure of entanglement of mixed states
Effectively classical quantum states for open systems
No full textBlanchard P, Olkiewicz R. Effectively classical quantum states for open systems. PHYSICS LETTERS A. 2000;273(4):223-231.Notions of robust and 'classical' states for an open quantum system are introduced and discussed in the framework of the isometric-sweeping decomposition. Using the predictability sieve proposed by Zurek [Phys. Rev. D 24 (1981) 1516; 26 (1982) 1862], 'quasi-classical' states are defined. A number of examples illustrating how the 'quasi-classical' states correspond to classical points in phase space connected with the measuring apparatus are presented. (C) 2000 Published by Elsevier Science B.V
From quantum to quantum via decoherence
No full textBlanchard P, Lugiewicz P, Olkiewicz R. From quantum to quantum via decoherence. PHYSICS LETTERS A. 2003;314(1-2):29-36.Various physical effects resulting from decoherence are discussed in the algebraic framework. In particular, it is shown that the environment may induce not only classical properties like superselection rules, pointer states or even classical behavior of the quantum system, but, what is more, it also allows the transition from statistical description of infinite quantum systems to quantum mechanics of systems with a finite number of degrees of freedom. It is shown that such transition holds for the quantum spin system in the thermodynamic limit interacting with the phonon field. (C) 2003 Elsevier B.V. All rights reserved
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