Josephson tunneling through a Yu-Shiba-Rusinov state: Interplay of $\pi$-shifts in Josephson current and local superconducting order parameter

Andreas Theiler, Christian R. Ast, Annica M. Black-Schaffer

An impurity hosting a magnetic moment coupled to a conventional $s$-wave superconductor gives rise to so-called Yu-Shiba-Rusinov (YSR) states with energies inside the superconducti…