Magnetic impurities in a two-dimensional superfluid Fermi gas with spin-orbit coupling

Abstract

We study magnetic impurities in a two dimensional superfluid Fermi gas with the spin-orbit coupling and find that the spin-orbit coupling makes some dramatic impacts on the effects of magnetic impurities. For the single impurity problem, we find that the number of bound states localized around the magnetic impurity is doubled. For the finite concentration n of impurities, we find that the energy gap is reduced and the density of states in the gapless region is greatly modified; there exists a gapless superfluid and N(ω) ∝ ω in the small ω limit.