Coherence susceptibility as a probe of quantum phase transitions

TL;DR

The paper proposes a coherence susceptibility method to detect quantum phase transitions without prior knowledge of order parameters, effectively identifying transition points and quantum criticality at finite temperatures.

Contribution

It introduces a novel coherence susceptibility approach that signals quantum fluctuations and accurately identifies quantum phase transitions without system bipartition considerations.

Findings

Successfully identifies quantum phase transition points

Pinpoints quantum criticality temperature frames

Aligns with recent experimental results

Abstract

We introduce a coherence susceptibility method, based on the fact that it signals quantum fluctuations, for identifying quantum phase transitions, which are induced by quantum fluctuations. This method requires no prior knowledge of order parameter, and there is no need for careful considerations concerning the choice of a bipartition of the system. It can identify different types of quantum phase transition points exactly. At finite temperatures, where quantum criticality is influenced by thermal fluctuations, our method can pinpoint the temperature frame of quantum criticality, which perfectly coincides with recent experiments.