Topological $p_{x}+ip_{y}$ Superfluid Phase of a Dipolar Fermi Gas in a 2D Optical Lattice

TL;DR

This paper demonstrates that a topological $p_{x}+ip_{y}$ superfluid phase can be realized in a 2D dipolar Fermi gas within an optical lattice, with potential applications in topological quantum computing.

Contribution

It shows how to achieve and analyze the topological superfluid phase in a dipolar Fermi gas with attractive interactions in a 2D optical lattice, including phase diagram and transition temperature.

Findings

The $p_{x}+ip_{y}$ superfluid phase is stable at low temperatures across all filling factors in the weak-coupling limit.

Phase separation occurs at higher interaction strengths near certain filling factors.

The transition temperature for the superfluid state is estimated for experimental relevance.

Abstract

In a dipolar Fermi gas, the anisotropic interaction between electric dipoles can be turned into an effectively attractive interaction in the presence of a rotating electric field. We show that the topological $p_{x}+ip_{y}$ superfluid phase can be realized in a single-component dipolar Fermi gas trapped in a 2D square optical lattice with this attractive interaction at low temperatures. The $p_{x}+ip_{y}$ superfluid state has potential applications for topological quantum computing. We obtain the phase diagram of this system at zero temperature. In the weak-coupling limit, the p-wave superfluid phase is stable for all filling factors. As the interaction strength increases, it is stable close to filling factors $n=0$ or $n=1$, and phase separation takes place in between. When the interaction strength is above a threshold, the system is phase separated for any $0<n<1$. The transition temperature of the $p_{x}+ip_{y}$ superfluid state is estimated and the implication for experiments is discussed.