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

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 Neel and the dimerized phases have been identified. Moreover, canted Neel 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.

Automated summary

The ground state phase diagram of the dimerized spin-1/2 XX honeycomb model in the presence of a transverse magnetic field is investigated using numerical exact techniques. The quantum correlations, concurrence, and quantum discord among nearest-neighbor spins are analyzed, demonstrating their ability to capture the position of quantum critical points and provide information on long-ranged critical correlations. Additionally, a magnetic-entanglement behavior starting from the saturation field is addressed.