LAUSR

The thermal entanglement in the two-qubit Ising spin chain in the presence of the Dzyaloshinski-Moriya(DM) anisotropic antisymmetric interaction in a nonuniform magnetic field is investigated. The influences of the DM coupling constant D, the temperature T, the uniform external magnetic field B and the nonuniform magnetic field h on the thermal entanglement measured by the concurrence C are studied in detail. The results show that both the increasing T and |B| decrease the C, but the increasing D develops the C, and D can also heighten the values of the threshold magnetic field |Bt| and the temperature Tt above which the thermal entanglement vanishes. And for a definite D, the increasing T makes the |Bt| become bigger as well. By comparison, before and after the critical temperature Tc, the h has different effects on C. Within a certain temperature range, the increasing h makes the C rise firstly and then fall. What’s more, as the h increases, the key temperature Tk at which the C reaches the maximum value increases. As a result, the thermal entanglement can be controlled by adjusting the values of B, h, D and T in various terrible environment, such as in strong external magnetic field, or high temperature environment, which will be useful in the research of quantum information in solid systems.