The manifestation of quantum resonances and antiresonances in a finite temperature dilute atomic gas

Abstract

We investigate the effect of temperature on resonant and antiresonant dynamics in a dilute atomic gas kicked periodically by a standing wave laser field. Our numerical calculations are based on a Monte Carlo method for an incoherent mixture of non-interacting plane waves, and show that the atomic dynamics are highly sensitive to the initial momentum width of the gas. We explain this sensitivity by examining the time evolution of individual atomic centre of mass momentum eigenstates with varying quasimomentum, and we have determined analytic expressions for the evolution of the second-order momentum moment to illustrate the range of behaviours.