Multiple Vortex Cores in 2D Electronic Systems with Proximity Induced Superconductivity

TL;DR

This paper predicts the formation of multiple vortex cores in 2D electronic systems with proximity-induced superconductivity, revealing a two-scale LDOS behavior and spectral features observable in tunneling experiments.

Contribution

It introduces the concept of multiple vortex cores with distinct LDOS behaviors in 2D superconducting layers, depending on tunneling coherence.

Findings

Multiple vortex cores exhibit two-scale LDOS behavior.

Spectral splitting and multiple peaks are predicted in tunneling spectroscopy.

Distinct features depend on tunneling coherence.

Abstract

The structure of a proximity induced vortex core in a two-dimensional (2D) metallic layer covering a superconducting half-space is calculated. We predict formation of a multiple vortex core characterized by two-scale behavior of the local density of states (LDOS). For coherent tunnelling between the 2D layer and the bulk superconductor, the spectrum has two subgap branches while for incoherent tunnelling only one of them remains. The resulting splitting of the zero-bias anomaly and the multiple peak structure in the LDOS should be visible in the tunnelling spectroscopy experiments.