Scattering mechanism of work done on an ultracold Fermi gas by a time-dependent interaction

Abstract

We discuss the work done on repulsive ultracold Fermi gas via collisions tuned by a time-dependent magnetic ramp. If the interaction is strengthened during binary collisions, the kinetic energy of atoms increases with each such inelastic event. The net energy transfer via collisions is compared with the transfer via the mean field. It is found that for a weak interaction, with a scattering length shorter than the inverse mean momentum of atoms, the mean field dominates, while for a strong interaction, the majority of energy enters the gas via collisions.