Electronic structure of edge and vortex states in chiral mesoscopic superconductor

TL;DR

This paper analyzes the quasiparticle spectrum in a mesoscopic chiral superconductor disk, revealing how edge and vortex states hybridize and how external magnetic fields can control the resulting energy minigaps.

Contribution

It provides an exact expression for surface state spectra and explores how magnetic fields influence the hybridization and minigap formation in vortex-edge state interactions.

Findings

Exact spectrum of surface states derived

Hybridization causes minigaps in quasiparticle spectrum

Magnetic field controls minigap width and density of states

Abstract

We study a subgap quasiparticle spectrum in a mesoscopic disk of chiral superconductor. We find an exact expression for the spectrum of surface states localized at the disk edge. Considering an Abrikosov vortex placed at the center of a superconducting disk we investigate the spectrum transformation near the intersection points of surface and vortex anomalous energy branches . The resulting splitting of the anomalous branches due to the hybridization of edge and vortex states is determined by an external magnetic field and can lead in particular to the formation of a set of minigaps in the quasiparticle spectrum. Tuning the external magnetic field makes it possible to control the width of minigaps and the positions of corresponding density of states singularities at the minigaps edges.