Entanglement and quantum correlations in the XX spin-1/2 honeycomb lattice

Abstract

The ground state phase diagram of the dimerized spin-1/2 XX honeycomb model in presence of a transverse magnetic field (TF) is known. With the absence of the magnetic field, two quantum phases, namely, the Néel and the dimerized phases have been identified. Moreover, canted Néel and the paramagnetic (PM) phases also emerge by applying the magnetic field. In this paper, using two powerful numerical exact techniques, Lanczos exact diagonalization, and Density matrix renormalization group (DMRG) methods, we study this model by focusing on the quantum correlations, the concurrence, and the quantum discord (QD) among nearest-neighbor spins. We show that the quantum correlations can capture the position of the quantum critical points in the whole range of the ground state phase diagram consistent with previous results. Although the concurrence and the QD are short-range, informative about long-ranged critical correlations. In addition, we address a ”magnetic-entanglement” behavior that starts from an entangled field around the saturation field.

Quantum correlations in the frustrated XY model on the honeycomb lattice

“…Inspired by the pivotal role of quantum correlations in identifying the critical quantum phase transition points, which encompass both symmetry and topological properties, we embark on a series of numerical analyses of the ground state phase diagram of the spin-1/2 XY frustrated honeycomb model. By delving into the concepts of quantum entanglement, we reveal a distinctive way of understanding strongly correlated systems close to their critical thresholds 41 .…”