DYNAMICS OF EXCITATIONS IN MOLECULAR CONDENSATES UNDER THE INFLUENCE OF AN ULTRASHORT-PULSE

A new method for the description of simultaneous creation, annihilatio n, propagation and relaxation of excitations in exciton (electron) sys tems interacting with a phonon bath and an ultrashort quantum optical pulse is developed on the basis of generalized master equations derive d by using a time-dependent projector. It is shown, that standard theo ries starting from an already created excitation at a given place, wit hout any off-diagonal elements of the exciton density matrix, have a v ery limited area of application because off-diagonal elements are gene rally nonzero once the excited pulse switches off Derived equations al so describe the influence of quantum statistics of the pulse.