Quantum discord and quantum phase transition in spin-1/2 frustrated Heisenberg chain

TL;DR

This paper investigates how quantum discord and geometric measures can detect quantum phase transitions in a spin-1/2 frustrated Heisenberg chain, providing analytical and numerical insights into their effectiveness.

Contribution

It derives analytical expressions for quantum discord and geometric measures in a frustrated Heisenberg chain and links these to phase transition detection and frustration properties.

Findings

GMQD and QD detect quantum phase transitions effectively.

Analytical expressions for QD and GMQD are obtained for small systems.

GMQD shows nonlinear dependence on frustration.

Abstract

By using the concept of the quantum discord (QD), we study the spin-1/2 antiferromagnetic Heisenberg chain with next-nearest-neighbor interaction. Due to the SU(2) symmetry and $Z_{2}$ symmetry in this system, we obtain the analytical result of the QD and its geometric measure (GMQD), which is determined by the two-site correlators. For the 4-site and 6-site cases, the connection between GMQD (QD) and the eigenenergies was revealed. From the analytical and numerical results, we find GMQD (QD) is an effective tool in detecting both the first-order and the infinite-order quantum-phase-transition points for the finite-size systems. Moreover, by using the entanglement excitation energy and a universal frustration measure we consider the frustration properties of the system and find a nonlinear dependence of the GMQD on the frustration.