Quantum correlations in the frustrated XY model on the honeycomb lattice

TL;DR

This paper investigates the quantum correlations in the frustrated XY honeycomb model, providing evidence that the intermediate phase is entangled and consistent with a quantum spin-liquid state.

Contribution

It offers a detailed numerical analysis of quantum correlations in the model, supporting the existence of an entangled quantum spin-liquid phase.

Findings

The intermediate phase shows significant entanglement.

Quantum discord and entanglement entropy indicate a spin-liquid state.

Numerical methods confirm the entangled nature of the phase.

Abstract

We consider the spin-$1/2$ XY frustrated antiferromagnetic Heisenberg honeycomb model. There is an unclear intermediate region in the ground state phase diagram of the model. The most recognized phases are the quantum spin-liquid (QSL) and the antiferromagnetic Ising ordering. From the viewpoint of the quantum correlations, the QSL phase is expected to be entangled. Motivated by this fact, we have calculated the concurrence, the quantum discord (QD), and the entanglement entropy, by using numerical Lanczos and density matrix renormalization group (DMRG) methods. Our results explicitly show that the intermediate region should be entangled supporting the QSL phase.