Topological superconductivity in Kondo-Kitaev model

TL;DR

This paper explores how topological superconductivity can emerge in the Kondo-Kitaev model on a honeycomb lattice, revealing phase transitions to topological superconducting states with Majorana edge modes.

Contribution

It introduces a new theoretical framework showing how Kondo coupling induces topological superconductivity in a Kitaev spin liquid system.

Findings

First order transition to ferromagnetic topological superconductor with chiral Majorana edge mode

Second order transition to paramagnetic topological superconductor with helical Majorana edge mode

Provides a novel route to realize topological superconductivity in Kondo lattice systems

Abstract

We investigate possible topological superconductivity in the Kondo-Kitaev model on the honeycomb lattice, where the Kitaev spin liquid is coupled to conduction electrons via the Kondo coupling. We use the self-consistent Abrikosov-fermion mean-field theory to map out the phase diagram. Upon increasing the Kondo coupling, a first order transition occurs from the decoupled phase of spin liquid and conduction electrons to a ferromagnetic topological superconductor of Class D with a single chiral Majorana edge mode. This is followed by a second order transition into a paramagnetic topological superconductor of Class DIII with a single helical Majorana edge mode. These findings offer a novel route to topological superconductivity in the Kondo lattice system. We discuss the connection between topological nature of the Kitaev spin liquid and topological superconductors obtained in this model.