title: Mixed quantum-classical description of spectroscopy of dissipative systems.
abstract: Mixed quantum-classical statistical mechanics is employed to calculate dipole moment correlation function and linear absorption spectra. A quantum two-level subsystem interacting with quantum vibrations (primary oscillators) which in turn are coupled to a classical bath composed of infinite set of harmonic oscillators is used as a dissipative system. Starting with mixed quantum-classical Liouville equation for the evaluation of the mixed quantum-classical dipole moment correlation function and using coherent states and the inverse of Baker-Campbell-Hausdorf formula to evaluate the trace over the primary oscillators, whereby, a closed analytical expression for the electronic dipole moment correlation function is obtained. Illustrations of several absorption spectra at different temperatures are provided. An approximate optical four-point correlation is obtained in the high temperature limit. A strategy for deriving an exact optical four-point correlation is suggested.
authors.affiliation: College of Science, Department of Chemistry, P.O. Box 17551, United Arab Emirates University, Al-Ain, United Arab Emirates. mtoutounji@uaeu.ac.ae
authors.forename: Mohamad
authors.initials: M
authors.lastname: Toutounji
mesh_terms: D002621:Chemistry / Q000379:methods*; D004583:Electrons; D015233:Models, Statistical; D008962:Models, Theoretical; D011789:Quantum Theory; D013053:Spectrophotometry / Q000379:methods*; D013269:Stochastic Processes; D013816:Thermodynamics