Effect of anharmonicity on energy relaxation of a dissipative quantum oscillator

Abstract

The effect of anharmonicity on the energy relaxation of excited state has been studied by means of a dissipative oscillator. The present study also sheds light on the recent femtosecond stimulated Raman spectroscopy results of Kovalenko et al. (J. Chem. Phys.139 011101 2013) on optical cooling of trans-stilbene. It has been shown that anharmonicity plays a crucial role in explaining the time-dependent frequency shift as well as the time evolution of bandwidth of $$\\nu _{C=C}$$νC=C mode of trans-stilbene in excited state, found in experiment.Graphical abstractThe effect of anharmonicity on the energy relaxation of a vibrationally excited state is presented in this paper. The paper also suggest that at initial stage IVR plays a key role in changing the effective temperature of optically excited molecule.