Critical Point Estimation and Long-Range Behavior in the One-Dimensional XY Model Using Thermal Quantum and Total Correlations

TL;DR

This paper analyzes how thermal quantum and total correlations in the one-dimensional XY model reveal critical points and long-range behavior, with measures sensitive to anisotropy and temperature effects.

Contribution

It introduces and compares various correlation measures for detecting critical points and factorized states in the XY model at finite temperature.

Findings

Correlation measures depend on anisotropy for critical point estimation.

Some measures detect the factorized ground state.

Temperature influences the range of correlations.

Abstract

We investigate the thermal quantum and total correlations in the anisotropic XY spin chain in transverse field. While we adopt concurrence and geometric quantum discord to measure quantum correlations, we use measurement-induced nonlocality and an alternative quantity defined in terms of Wigner-Yanase information to quantify total correlations. We show that the ability of these measures to estimate the critical point at finite temperature strongly depend on the anisotropy parameter of the Hamiltonian. We also identify a correlation measure which detects the factorized ground state in this model. Furthermore, we study the effect of temperature on long-range correlations.