Normal-Superfluid Interface Scattering For Polarized Fermion Gases

TL;DR

This paper investigates how temperature differences affect particle scattering at the normal-superfluid interface in imbalanced fermion gases, revealing exponential suppression of thermal conductivity and suggesting mechanisms for FFLO-like state formation.

Contribution

It introduces a mean-field analysis of N-SF interface scattering in polarized fermion gases, highlighting thermal transport suppression and potential gap oscillation mechanisms.

Findings

Thermal conductivity drops exponentially with increasing imbalance.

Temperature differences can block thermal equilibration.

Possible creation mechanism for FFLO-like states.

Abstract

We argue that, for the recent experiments with imbalanced fermion gases, a temperature difference may occur between the normal (N) and the gapped superfluid (SF) phase. Using the mean-field formalism, we study particle scattering off the N-SF interface from the deep BCS to the unitary regime. We show that the thermal conductivity across the interface drops exponentially fast with increasing $h/k_B T$, where $h$ is the chemical potential imbalance. This implies a blocking of thermal equilibration between the N and the SF phase. We also provide a possible mechanism for the creation of gap oscillations (FFLO-like states) as seen in recent studies on these systems.