Presence Of Time-dependent Field Research Articles

Semiclassical theory of double-pulse spectra for time dependent systems

A theory of double-pulse photodetachment spectra in the presence of time dependent field has been developed. We derived a general formula for the total population generated by the double-pulse laser applying the time dependent closed orbit theory. We analyzed the double-pulse spectra for H− in the presence of constant electric field superposed with a sinusoidal time dependent field. The effects of the amplitude of time dependent field and laser parameters have been investigated. It has been shown that the population has peak or valley when the time delay between the two pulses of the double-pulse laser is equal to the time of the closed orbit emanating at the peak of the first pulse of the double-pulse laser. We also shown that the laser phase parameter modulates the population.

Stochastic quantum molecular dynamics for finite and extended systems

We present a detailed account of the technical aspects of stochastic quantum molecular dynamics, an approach introduced recently by the authors [H. Appel, M. Di Ventra, Phys. Rev. B 80 (2009) 212303] to describe coupled electron–ion dynamics in open quantum systems. As example applications of the method we consider both finite systems with and without ionic motion, as well as describe its applicability to extended systems in the limit of classical ions. The latter formulation allows the study of important phenomena such as decoherence and energy relaxation in bulk systems and surfaces in the presence of time-dependent fields.