Decoherence for phase-sensitive relaxation

It is shown that the vibrational wave packet relaxation of initially coherent (displaced) states as well as the quantum superposition of coherent states in heat baths with different spectral densities exhibit a number of peculiarities compared with the cases of linear phase-sensitive relaxation, quadratic relaxation, and relaxational dynamics described with the use of Zurek's environmentally induced pointer basis. A strong dependence of the relaxation rate on the position of the spectral density maximum of the bath is found. The differences can be used for the discrimination of the mechanisms of the molecule-environment interactions. (C) 2001 Elsevier Science B.V. All rights reserved.