Supersolid Phase of Cold Fermionic Polar Molecules in 2D Optical Lattices

TL;DR

This paper investigates the phase diagram of ultra-cold fermionic polar molecules in 2D optical lattices, revealing the stabilization of supersolid phases due to long-range dipole interactions and their thermal melting behavior.

Contribution

It provides the first detailed zero-temperature and finite-temperature phase diagrams for supersolid phases in 2D fermionic polar molecule systems.

Findings

Supersolid phase is stabilized by dipole-dipole interactions.

Large parameter region where supersolids can be observed.

Finite temperature phase diagram showing melting of supersolids.

Abstract

We study a system of ultra-cold fermionic polar molecules in a two-dimensional square lattice interacting via both the long-ranged dipole-dipole interaction and a short-ranged on-site attractive interaction. Singlet superfluid, charge density wave, and supersolid phases are found to exist in the system. We map out the zero temperature phase diagram and find that the supersolid phase is considerably stabilized by the dipole-dipole interaction and thus can exist over a large region of filling factors. We study the melting of the supersolid phase with increasing temperature, map out a finite temperature phase diagram of the system at fixed filling, and determine the parameter region where the supersolid phase can possibly be observed in experiments.