Magnetic Impurities in Two-Dimensional Superfluid Fermi Gas with Spin-Orbit Coupling

TL;DR

This paper investigates how spin-orbit coupling significantly alters the effects of magnetic impurities in a two-dimensional superfluid Fermi gas, affecting bound states and the energy gap.

Contribution

It reveals the dramatic impact of spin-orbit coupling on magnetic impurity effects, including doubling bound states and modifying the density of states.

Findings

Number of bound states around a magnetic impurity is doubled.

Energy gap is reduced with finite impurity concentration.

Density of states in the gapless region is significantly altered.

Abstract

We consider magnetic impurities in a two dimensional superfluid Fermi gas in the presence of spin-orbit coupling. By using the methods of t-matrix and Green's function, we find spin-orbit coupling has some dramatic impacts on the effects of magnetic impurities. For the single impurity problem, the number of bound states localized around the magnetic impurity is doubled. For the finite concentration $n$ of impurities, the energy gap is reduced and the density of states in the gapless region is greatly modified.