Liquid and crystal phase of dipolar fermions in two dimensions

TL;DR

This study uses quantum Monte Carlo methods to explore the phases of a two-dimensional dipolar Fermi gas, identifying the liquid and crystal states, and analyzing phase transitions at zero temperature.

Contribution

It provides a detailed quantum Monte Carlo analysis of the liquid and Wigner crystal phases, including phase transition points and the absence of stripe phases.

Findings

Calculated the equation of state for liquid and crystal phases

Identified the critical density for liquid-solid transition

Found no energetic favorability for stripe phases

Abstract

The liquid and crystal phase of a single-component Fermi gas with dipolar interactions are investigated using quantum Monte Carlo methods in two spatial dimensions and at zero temperature. The dipoles are oriented by an external field perpendicular to the plane of motion, resulting in a purely repulsive 1/r^3 interaction. In the liquid phase we calculate the equation of state as a function of the interaction strength and other relevant properties characterizing the Fermi-liquid behavior: effective mass, discontinuity at the Fermi surface and pair correlation function. In the high density regime we calculate the equation of state of the Wigner crystal phase and the critical density of the liquid to solid first order phase transition. Close to the freezing density we also search for the existence of a stripe phase, but such a phase is never found to be energetically favorable.