Superconductor Vortex Spectrum Including Fermi Arc States in Time-Reversal Symmetric Weyl Semimetals

TL;DR

This paper derives the vortex spectrum in time-reversal symmetric Weyl semimetals, revealing how Fermi arc states and Berry phases influence vortex properties, and proposes experimental detection in candidate materials.

Contribution

It introduces a semiclassical approach to calculate vortex spectra in Weyl semimetals, incorporating Fermi arc and bulk chiral modes, and predicts novel phenomena like nonlocal Majorana modes.

Findings

Vortex spectrum depends on Berry phase of Fermi arc orbits.

Tilting vortices induces transitions between bosonic, fermionic, and supersymmetric states.

Periodic peaks in density of states indicate nonlocal Majorana modes.

Abstract

Using semiclassics to surmount the hurdle of bulk-surface inseparability, we derive the superconductor vortex spectrum in non-magnetic Weyl semimetals and show that it stems from the Berry phase of orbits made of Fermi arcs on opposite surfaces and bulk chiral modes. Tilting the vortex transmutes it between bosonic, fermionic and supersymmetric, produces periodic peaks in the density of states that signify novel nonlocal Majorana modes, and yields a thickness-independent spectrum at ``magic angles''. We propose (Nb,Ta)P as candidate materials and tunneling spectroscopy as the ideal experiment.