Detecting Quantum Critical Points using Bipartite Fluctuations

TL;DR

This paper introduces bipartite fluctuations as an efficient and accurate method for detecting quantum phase transitions in strongly correlated systems, outperforming entanglement entropy especially in one dimension and applicable in higher dimensions.

Contribution

The study demonstrates bipartite fluctuations as a superior tool for identifying quantum critical points across various dimensions, with potential experimental applications.

Findings

Bipartite fluctuations outperform entanglement entropy in detecting quantum critical points.

F accurately locates quantum phase transitions without prior knowledge of universality class.

Method applicable to quantum spins and bosons, including higher-dimensional systems.

Abstract

We show that the concept of bipartite fluctuations F provides a very efficient tool to detect quantum phase transitions in strongly correlated systems. Using state of the art numerical techniques complemented with analytical arguments, we investigate paradigmatic examples for both quantum spins and bosons. As compared to the von Neumann entanglement entropy, we observe that F allows to find quantum critical points with a much better accuracy in one dimension. We further demonstrate that F can be successfully applied to the detection of quantum criticality in higher dimensions with no prior knowledge of the universality class of the transition. Promising approaches to experimentally access fluctuations are discussed for quantum antiferromagnets and cold gases.