Crossover-Time in Quantum Boson and Spin Systems

Gennady P. Berman, Evgeny N. Bulgakov, Darryl D. Holm (Autoren)

Buch | Softcover

XI, 268 Seiten

2013 | 1. Softcover reprint of the original 1st ed. 1994
Springer Berlin (Verlag)
978-3-662-14506-7 (ISBN)

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We consider quantum dynamical systems (in general, these could be either Hamiltonian or dissipative, but in this review we shall be interested only in quantum Hamiltonian systems) that have, at least formally, a classical limit. This means, in particular, that each time-dependent quantum-mechanical expectation value X (t) has as i cl Ii -+ 0 a limit Xi(t) -+ x1 )(t) of the corresponding classical sys tem. Quantum-mechanical considerations include an additional di mensionless parameter f = iiiconst. connected with the Planck constant Ii. Even in the quasiclassical region where f~ 1, the dy namics of the quantum and classicalfunctions Xi(t) and XiCcl)(t) will be different, in general, and quantum dynamics for expectation val ues may coincide with classical dynamics only for some finite time. This characteristic time-scale, TIi., could depend on several factors which will be discussed below, including: choice of expectation val ues, initial state, physical parameters and so on. Thus, the problem arises in this connection: How to estimate the characteristic time scale TIi. of the validity of the quasiclassical approximation and how to measure it in an experiment? For rather simple integrable quan tum systems in the stable regions of motion of their corresponding classical phase space, this time-scale T"" usually is of order (see, for example, [2]) const TIi. = p,li , (1.1) Q where p, is the dimensionless parameter of nonlinearity (discussed below) and a is a constant of the order of unity.

Method of Coherent States.- The Exact C-Number Equation for Time-Dependent Expectation Values in Coherent States.- Quasiclassical Perturbation Theory for Time-Dependent Expectation Values with Quantum Nonlinear Hamiltonians.- The Characteristic Times of Violation of Quasiclassical Approximation for Integrable Boson and Spin Systems.- Time-Scale ?? for a Kicked Quantum Nonlinear Oscillator.- The Time of Applicability of the Quasiclassical Approach in a Boson System of Two Interacting Quantum Nonlinear Resonances.- Two Interacting Quantum Nonlinear Resonances in a Spin System.- Quantization of a Stochastic Web.- Characteristic Times for Chaotic Dynamics in Wigner Representation.- Quantum Chaos of Atoms in a Resonant Cavity.- Quantum Chaos of Atoms in a Resonant Cavity Driven by an External Resonant Field.- Violation of the Semiclassical Approximation and Quantum Chaos in a Paramagnetic Spin System.- Weak Quantum Chaos in a System of N Atoms in a Resonant Cavity Interacting with an External Resonant Field.- Quantum Dynamics in Stationary Coherent States (SCS).- Discussion.

"...an attractive introduction to some of the key mathematical and physical concepts of importance to an understanding of such systems and to the general area of quantum chaos. As such it deserves a much wider audience than its title might at first glance suggest." Contemporary Physics

Erscheint lt. Verlag	10.11.2013
Reihe/Serie	Lecture Notes in Physics Monographs
Zusatzinfo	XI, 268 p. 5 illus.
Verlagsort	Berlin
Sprache	englisch
Maße	155 x 235 mm
Gewicht	403 g
Themenwelt	Naturwissenschaften ► Physik / Astronomie ► Quantenphysik
Themenwelt	Naturwissenschaften ► Physik / Astronomie ► Theoretische Physik
Schlagworte	Chaos • Coherent states • crossover-time • kohärente Zustände • Quantenchaos • Quantum Chaos
ISBN-10	3-662-14506-5 / 3662145065
ISBN-13	978-3-662-14506-7 / 9783662145067
Zustand	Neuware