Topological quantum phase transition in an extended Kitaev spin model

TL;DR

This paper investigates the continuous topological quantum phase transition between Abelian and non-Abelian phases in an extended Kitaev model on a torus, highlighting the roles of entanglement and ground-state energy as indicators.

Contribution

It provides an analytical study of the phase transition in an extended Kitaev model, linking entanglement and energy to topological phase changes.

Findings

The phase transition is continuous.

Entanglement characterizes the topological transition.

Ground-state energy signals the phase change.

Abstract

We study the quantum phase transition between Abelian and non-Abelian phases in an extended Kitaev spin model on the honeycomb lattice, where the periodic boundary condition is applied by placing the lattice on a torus. Our analytical results show that this spin model exhibits a continuous quantum phase transition. Also, we reveal the relationship between bipartite entanglement and the ground-state energy. Our approach directly shows that both the entanglement and the ground-state energy can be used to characterize the topological quantum phase transition in the extended Kitaev spin model.