Generic Weyl phase in the vortex state of quasi-two-dimensional chiral superconductors

TL;DR

This paper explores the topological properties of Majorana modes in vortex states of quasi-2D chiral superconductors, revealing a generic Weyl phase and quantum phase transitions driven by magnetic field and Fermi energy.

Contribution

It demonstrates the existence of a generic Weyl phase in the vortex state of quasi-2D chiral superconductors and analyzes topological phase transitions of Majorana bands.

Findings

Majorana modes form a topologically non-trivial band structure.

Quantum phase transitions alter the topological nature of Majorana bands.

A generic superconducting Weyl phase exists in low magnetic fields.

Abstract

We study the collective behavior of Majorana modes in the vortex state of chiral $p$-wave superconductors. Away from the isolated vortex limit, the zero-energy Majorana states communicate with each other on a vortex lattice, and form a coherent band structure with non-trivial topological character. We revealed that the topological nature of Majorana bands changes sensitively via quantum phase transitions in the two-dimensional (2D) systems, as sweeping magnetic field or Fermi energy. Through the dimensional reduction, we showed the existence of generic superconducting Weyl phase in a low magnetic field region of quasi-2D-chiral superconductors.