Decoherence for phase-sensitive relaxation

It is shown that the vibrational wave packet relaxation of initially cohere nt (displaced) states as well as the quantum superposition of coherent stat es in heat baths with different spectral densities exhibit a number of pecu liarities compared with the cases of linear phase-sensitive relaxation, qua dratic relaxation, and relaxational dynamics described with the use of Zure k's environmentally induced pointer basis. A strong dependence of the relax ation rate on the position of the spectral density maximum of the bath is f ound. The differences can be used for the discrimination of the mechanisms of the molecule-environment interactions. (C) 2001 Elsevier Science B.V. Al l rights reserved.