Correlation-induced coherence and its use in detecting quantum phase transitions

TL;DR

This paper introduces a new coherence-based measure that effectively detects quantum phase transitions by capturing both coherence and correlations, demonstrated on the XXZ and Kitaev models.

Contribution

It proposes a novel measure based on the degree of coherence and susceptibility, improving detection of quantum phase transitions over previous methods.

Findings

The measure detects QPTs in the XXZ model.

It effectively identifies QPTs in the Kitaev honeycomb model.

Outperforms many existing proposals for QPT detection.

Abstract

The past two decades have witnessed a surge of interest in exploring correlation and coherence measures to investigate quantum phase transitions (QPTs). Here, motivated by the continued push along this direction, we propose a measure which is built upon the so-called degree of coherence, and advocate using the susceptibility of our measure to detect QPTs. We show that our measure can capture both the notions of coherence and correlations exhibited in bipartite states and therefore represents a hybrid of these two notions. Through examining the XXZ model and the Kitaev honeycomb model, we demonstrate that our measure is favorable for detecting QPTs in comparison to many previous proposals.