J. Perina, DYNAMICS OF EXCITATIONS IN MOLECULAR CONDENSATES UNDER THE INFLUENCE OF AN ULTRASHORT-PULSE, Journal of physics. A, mathematical and general, 30(23), 1997, pp. 8105-8117
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.