Time-Dependent Spectrum of a Two-Level System Coupled to a Heat Bath Driven by Pulsed Laser

Abstract

A two-level system diagonally coupled to a heat bath consisting of harmonic oscillators with a proper frequency spectrum producing a Markoffian random perturbation is considered. Assuming relatively weak or fast modulation conditions, we calculate spectra from the system driven by a continuous wave and a pulsed laser of arbitrary strength by applying the physical spectrum proposed by Eberly and Wódkiewicz. The results give the coherent and the incoherent spectra; clarification of how dynamical evolution of these components is influenced by the change of physical parameters is obtained.