Strongly interacting p-wave Fermi gas in two dimensions: Universal relations and breathing mode

Abstract

The contact is an important concept that characterizes the universal properties of a strongly interacting quantum gas. It appears in both thermodynamic (energy, pressure, etc.) and dynamic quantities (radio-frequency and Bragg spectroscopies, etc.) of the system. Very recently, the concept of contact was extended to higher partial waves; in particular, the p-wave contacts have been experimentally probed in recent experiments. So far, discussions on p-wave contacts have been limited to three dimensions. In this paper, we generalize the p-wave contacts to two dimensions and derive a series of universal relations, including the adiabatic relations, high-momentum distribution, virial theorem, and pressure relation. At the high-temperature and low-density limit, we calculate the p-wave contacts explicitly using virial expansion. A formula which directly connects the shift of the breathing-mode frequency and the p-wave contacts is given in a harmonically trapped system. Finally, we also derive the relationships between interaction parameters in three- and two-dimensional Fermi gases and discuss possible experimental realization of a two-dimensional Fermi gas with p-wave interactions.