Topological indices, defects and Majorana fermion in chiral superconductors

TL;DR

This paper investigates how topological invariants protect Majorana fermions in 2D chiral superconductors, revealing a complex phase diagram and analyzing the stability and interference of Majorana modes.

Contribution

It introduces a detailed topological phase diagram for 2D chiral superconductors and explores the protection and stability of Majorana fermions related to topological invariants.

Findings

Multiple topological phases characterized by Z and Z2 invariants.

Majorana fermions appear at edges, dislocations, and vortex cores.

Interference effects influence Majorana fermion stability.

Abstract

We study theoretically the role of topological invariants to protect the Majorana fermions in a model of two-dimensional chiral superconductors which belong to class D of topological periodic table. A rich phase diagram is revealed. Each phase is characterized by the topological invariants for 2d (Z) and 1d (Z2), which lead to the Majorana fermion at the edge of the dislocation and the core of the vortex. Interference of the Majorana fermions originated from the different topological invariants is studied. The stability of the Majorana fermion with respect to the interlayer coupling, i.e., in 3d, is also examined.