Yu-Shiba-Rusinov states in two-dimensional superconductors with arbitrary Fermi contours

Abstract

Magnetic impurities on a superconductor induce subgap Yu-Shiba-Rusinov (YSR) bound states, localized at the impurity site, decaying over distances dependent on microscopical details. Here, the authors present an effective model providing analytical expressions of their spatial distribution for a two-dimensional superconductor with an arbitrary Fermi contour. These results prove that vector nesting in anisotropic Fermi contours focuses YSR states into one-dimensional-like beams, extending to coherence length scales. The authors check the accuracy of the approximation by comparing the results to an exact numerical calculation based on a tight-binding Hamiltonian and to STM results on Mn dimers on a superconductor.