Elastic collision rates of spin-polarized fermions in two dimensions

Abstract

We study the $p$-wave elastic collision rates in a two-dimensional spin-polarized ultracold Fermi gas in the presence of a $p$-wave Feshbach resonance. We derive the analytical relation of the elastic collision rate coefficient in the close vicinity of resonance when the effective range is dominant. The elastic collision rate is enhanced by an exponential scaling of $e^{-q_{r}^{2} / q_{T}^{2}}$ towards the resonance. Here, $q_{r}$ is the resonant momentum and $q_T$ is the thermal momentum. An analogous expression is derived for the case of three dimensions successfully explains the thermalization rates measurement in the recent experiment~[Phys. Rev. A 88, 012710 (2013)]. In the zero-range limit where the effective range is negligible, the elastic collision rate coefficient is proportional to temperature $T^2$ and scattering area $A_{p}^2$. In this limit, energy transfer from high to low velocity through $p$-wave collision is approximately $\sqrt{2}$ times faster compared to the three-dimensional case. We also discuss the collisional stability in the presence of three-body losses in the background scattering limit. Our results suggest that $p$-wave evaporation may be performed with improved efficiency and may provide insight into the dynamics of the system in experiments.