Fig. 1: Interaction between Caroli de Gennes Matricon (CdGM) and Yu Shiba Rusinov (YSR) states.
From: Coherent coupling between vortex bound states and magnetic impurities in 2D layered superconductors
a The YSR state is schematically represented by the red and blue dots with arrows representing the spin. The value of the superconducting gap as a function of the radius is shown in green for energies above and below the Fermi level. The CdGM states are schematically shown by colored circles. The difference in energy between levels, Δ2/2EF, with Δ the superconducting gap and EF the Fermi energy, is strongly exaggerated. Green arrow on top schematically represents the vortex core size ξV. The interaction between CdGM and YSR bound states leads to a spatial shift in the CdGM states, which is different for electron and hole components of the Local Density of States (LDOS) inside the superconducting gap, N(E > 0) (b) and N(E < 0) (c). In d we show line profiles of the images in b (blue-green) and of c (magenta). We also show a profile of their difference in orange. In e we show the difference image between b and c. The LDOS is larger along the direction of the YSR impurity. This occurs for a hole band and a single impurity. For an electron band, we expect the opposite result. The position of the YSR impurity is represented by a black dot and the vortex core center by the crossing point between lines in b, c, d, and e.
