Quantum correlations in the frustrated XY model on the honeycomb lattice

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.