Magnetic field-dependent inhomogeneities and their effect on the magnetoresponse of 2D superconductors

Abstract

We show that inhomogeneities in the spatial distribution of Cooper pairs and in the phase of the local superconducting order parameter in the vicinity of a superconductor-normal state transition (SNT) in two dimensions can be highly sensitive to a perpendicular magnetic field. We focus on the role of orbital effects in the field-dependence of local superfluid stiffness and superconducting phase disorder in homogeneously-disordered two-dimensional superconductor thin films. The relative importance of these orbital effects is analyzed in different physical regimes dominated by Coulomb blockade, thermal phase fluctuations and Aharanov-Bohm phase disorder respectively. Following this approach, we obtain explicit expressions for the field dependence of magnetoresistance and superfluid stiffness near the SNT, and attempt an understanding of some recent experimental findings.