Topological phase transition induced by Zeeman field in topological insulator/superconductor heterostructure

TL;DR

This paper studies how a Zeeman field induces a topological phase transition in a topological insulator/superconductor heterostructure, revealing conditions for the emergence of Majorana fermions at vortex cores.

Contribution

It demonstrates that Majorana fermions can exist in a phase with zero first Chern number, supported by the index theorem, in a topological insulator/superconductor system under magnetic field.

Findings

Majorana fermion exists at vortex core in zero Chern number phase

Zeeman field induces a topological phase transition

Majorana fermions do not exist in the non-trivial Chern number phase

Abstract

We investigate a topological insulator -- superconductor heterostructure with an Abrikosov vortex in a magnetic field. Large Zeeman field causes a topological phase transition in the system. We found that a Majorana fermion exists at the vortex core in the phase with zero first Chern number and does not exist at the phase with non-trivial first Chern number. This result is supported by the index theorem. This system provides an example in which a Majorana fermion emerges in a system with zero first Chern number.