Breached Superfluidity via P-Wave Coupling

TL;DR

This paper introduces a stable breached superfluid state arising from p-wave coupling between fermions with mismatched Fermi surfaces, leading to coexistence of superfluid and normal phases in a homogeneous system.

Contribution

It demonstrates the stability of a breached superfluid phase with p-wave pairing under small Fermi surface mismatches and weak coupling, expanding understanding of superfluid states.

Findings

Breached superfluidity persists for small Fermi surface mismatch.

The state remains stable with weak p-wave coupling.

Coexistence of superfluid and normal components in a homogeneous phase.

Abstract

Anisotropic pairing between fermion species with different fermi momenta opens two-dimensional areas of gapless excitations, thus producing a spatially homogeneous state with coexisting superfluid and normal fluids. This breached pairing state is stable and robust for arbitrarily small mismatch and weak p-wave coupling.