Investigation of Quantum Correlations for A S = 1/2 Ising–Heisenberg Model on a Symmetrical Diamond Chain

We consider quantum correlations for a S = 1/2 Ising–Heisenberg model of a symmetrical diamond chain. First, we compare concurrence, quantum discord and 1-norm geometric quantum discord of an ideal diamond chain (Jm = 0) in the absence of magnetic field. The results show no simple ordering relations between these quantum correlations, so that quantum discord may be smaller or larger than the 1-norm geometric quantum discord, this observation contradicts the previous result provided by F. M. Paula [ 1]. Symmetrical behaviour of quantum correlation versus ferromagnetic and anti-ferromagnetic coupling constant J is considerable. The effect of external magnetic field B and temperature dependence is also considered. Furthermore, we study quantum discord and geometric measure of quantum discord with the effect of next nearest neighbour interaction between nodal Ising sites for a generalized diamond chain (Jm ≠ 0), and we observe coexistence of phases with different values of magnetic field for quantum correlations. Moreover, entanglement sudden death occurs while quantum discord, 1-norm geometric quantum discord and geometric measure of quantum discord are immune from sudden death.