Construct order parameter from the spectra of mutual information

TL;DR

This paper links quantum mutual information spectra to traditional order parameters, enabling the identification of phases with long-range order through entanglement analysis.

Contribution

It introduces a method to derive local order operators from mutual information spectra, bridging quantum information and condensed matter physics.

Findings

Mutual information at long distances indicates long-range order.

Entanglement spectra can be used to identify phase transitions.

A new approach to connect quantum information measures with order parameters.

Abstract

In this paper, we try to establish a connection between a quantum information concept, i.e. the mutual information, and the conventional order parameter in condensed matter physics. We show that a non-vanishing mutual information at a long distance means the existence of long-range order. By analyzing the entanglement spectra of the reduced density matrix that are used to calculate the mutual information, we show how to find the local order operator used to identify various phases with long-rang order.