The Journal of Chemical Physics

On the theory of homogeneous and inhomogeneous line broadening. An exactly solvable model

Ernst Walter Knapp, Sighart F. Fischer

Published Jan 1, 1981• 70 citations

Abstract

The simultaneous influence of homogeneous and inhomogeneous line-broadening mechanisms are investigated for a reference system embedded in a medium. An analytically solvable model is constructed which includes the interaction of the reference mode with N strongly coupled environmental states (causing an inhomogeneity) and weakly coupled bath states. The modulation of the reference mode is caused by transitions between the strongly coupled perturber states. These may be switched on with a different rate than they are switched off. Consequently, effects of energy of activation and the change in entropy for environmental transitions on the line shape can be analyzed. The spectral function as well as the relaxation function are discussed as a function of the relevant parameters such as the number of perturbers, the lifetime T1, the temperature, and transition rates.

DOI: 10.1063/1.440798

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