Crossover-Time in Quantum Boson and Spin Systems

This monograph compares classical and quantum dynamics for unstable (chaotic) systems. Characteristic times for divergence of classical and quantum solutions are estimated, and examples of classical-quantum "crossover-times" are provided. The book can be recommended to graduate students and to specialists.

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.