Quantum dynamics of a time-dependent multidimensional non-linear oscillator and modelling of ultrafast intensity oscillations in charge transfer spectra

Abstract

Quantum dynamics of a coupled two-dimensional non-linear oscillator which has its harmonic frequencies varying with time is worked out in a time-dependent variational as well as perturbative framework. The time-dependent variational calculations are done by invoking the time-dependent Fourier grid Hamiltonian method. A more general case in which the harmonic frequencies, along with the equilibrium positions, are allowed to vary with time is also investigated. The model is used to interpret ultrafast intensity oscillations that may accompany an intramolecular charge transfer transition in which the time scales of charge separation and vibration are not widely different and therefore temporally non-separable.