Predicted Multiple Cores of a Magnetic Vortex Threading a Two-Dimensional Metal Proximity Coupled to a Superconductor

The structure of a proximity induced vortex core in a two-dimensional metallic layer covering a superconducting half-space is calculated. We predict the formation of a multiple vortex core characterized by two-scale behavior of the local density of states. For coherent tunneling between the two-dimensional layer and the bulk superconductor, the spectrum has two subgap branches while for incoherent tunneling only one of them remains. The resulting splitting of the zero-bias anomaly and the multiple peak structure in the local density of states should be visible in the tunneling spectroscopy experiments. DOI: 10.1103/PhysRevLett.110.027003