The energy-level statistics in the core of a vortex in a p-wave superconductor

TL;DR

This paper investigates the energy-level statistics of quasiparticles in the vortex core of a disordered two-dimensional p-wave superconductor, revealing a novel universality class linked to the system's spin symmetry.

Contribution

It identifies a new universality class (class B) for energy-level statistics in vortex cores of p-wave superconductors, influenced by O(2) spin symmetry and disorder effects.

Findings

Energy levels follow the universality class B (orthogonal matrices in odd dimensions).

The universality class is robust against disorder, vector potential, and certain pairing admixtures.

Spin-orbit coupling and Zeeman splitting can alter the universality class.

Abstract

In the presence of strong disorder, the statistics of quasiparticle levels in the core of a vortex in a two-dimensional p-wave superconductor belongs to the universality class B corresponding to the ensemble of orthogonal matrices in odd dimensions. This novel universality class appears as a consequence of the O(2) spin symmetry of p-wave pairing. It is preserved in the presence of random disorder, of electromagnetic vector potential, and of an admixture of the pairing of opposite chirality in the vortex core, but may be destroyed by spin-orbit coupling and by Zeeman splitting.