Thermal quantum correlations of a spin-1/2 Ising–Heisenberg diamond chain with Dzyaloshinskii–Moriya interaction**Project supported by the National Natural Science Foundation of China (Grant No. 11274102), the New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-0960), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20134208110001).

Abstract

We investigate the properties of thermal quantum correlations in an infinite spin-1/2 Ising–Heisenberg diamond chain with Dzyaloshinskii–Moriya (DM) interaction. The thermal quantum discord (TQD) and the thermal entanglement (TE) are discussed as two kinds of important methods to measure the quantum correlation, respectively. It is found that DM interaction plays an important role in the thermal quantum correlations of the system. It can enhance the thermal quantum correlations by increasing DM interaction. Furthermore, the thermal quantum correlations can be promoted by tuning the external magnetic field and the Heisenberg coupling parameter in the antiferromagnetic system. It is shown that the behaviors of TQD differ from those of TE. TQD is more robust against decoherence than TE. For the measurement of TQD, the “regrowth” phenomenon occurs in the ferromagnetic system. We also find that the anisotropy favors the thermal quantum correlations of the system with weak DM interaction.