Crossover-Time in Quantum Boson and Spin Systems

Download or read book Crossover-Time in Quantum Boson and Spin Systems written by Gennady P. Berman and published by Springer Science & Business Media. This book was released on 2008-10-04 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors compare classical and quantum dynamics in the quasiclassical region of parameters and under the condition of unstable (chaotic) classical behavior. They estimate the characteristic time-scale at which classical and quantum solutions start to differ significantly. The method is based on exact equations for time-dependent expectation values in boson and spin coherent states, and applies to rather general Hamiltonians with many degrees of freedom. The authors develop a consistent dynamical theory for quantum nonintegrable Hamiltonians and provide explicit examples of classical-quantum "crossover-time", a very common and fundamental phenomenon in quantum nonintegrable systems. This book can be recommended to graduate students and to specialists.