Exotic phase diagram of a topological quantum system

TL;DR

This paper investigates the complex phase diagram of a topological quantum system, revealing new quantum phase transitions within the same topological class driven by singularities in nonlocal correlations.

Contribution

It uncovers novel quantum phase transitions between phases of the same topological class in the Kitaev model, expanding understanding of topological phase diagrams.

Findings

Identification of new QPTs within the same topological class

Singular behavior of nonlocal correlations at critical points

Existence of multiple topological phases with identical Chern numbers

Abstract

We study the quantum phase transitions (QPTs) in the Kitaev spin model on a triangle-honeycomb lattice. In addition to the ordinary topological QPTs between Abelian and non-Abelian phases, we find new QPTs which can occur between two phases belonging to the same topological class, namely, either two non-Abelian phases with the same Chern number or two Abelian phases with the same Chern number. Such QPTs result from the singular behaviors of the nonlocal spin-spin correlation functions at the critical points.