Superfluid theory of a gas of polarized dipolar Fermi molecules

TL;DR

This paper develops a superfluid theory for polarized dipolar Fermi gases, deriving a finite, predictive BCS gap equation and analyzing superfluid symmetry and Fermi surface deformation caused by anisotropic dipole interactions.

Contribution

It introduces a cutoff-free superfluid theory for dipolar Fermi gases, enabling accurate predictions of superfluid properties and order parameter symmetry.

Findings

The BCS gap equation is free from ultraviolet divergence.

The superfluid order parameter exhibits specific symmetry at zero temperature.

Fermi surface deformation is influenced by dipole interaction anisotropy.

Abstract

We present a superfluid theory of a polarized dipolar Fermi gas. For two dipolar molecules each of which consists of two atoms with positive charge and negative charge, we derive an effective dipole-dipole pairing interaction. Using this pairing interaction, we show that the resulting BCS gap equation is not suffered from the well-known ultraviolet divergence, so that one can quantitatively predict superfluid properties of a dipolar Fermi gas. Using this cutoff-free superfluid theory, we examine the symmetry of the superfluid order parameter at T=0. We also discuss the deformation of the Fermi surface, originating from the anisotropy of the dipole-dipole interaction.