Abstract： The pair-wise thermal entanglement in a four-qubit Heisenberg XXZ chain is investigated to study the role of anisotropy when an external magnetic field is included. It is found that pair-wise entanglement is absent between nearest- and next-nearest neighbouring qubits with anisotropic parameter Δ ≤ -1. For two nearest-neighbouring qubits, increasing the parameter can not only induce the entanglement, but also extend the entanglement region in terms of magnetic field B and temperature T. For two next-nearest-neighbouring qubits, increasing anisotropic parameter can shift the location of the entanglement and control the extent of the entanglement in terms of magnetic field at a finite temperature.
(Quantized spin models, including quantum spin frustration)
引用本文:
CAO Min;ZHU Shi-Qun. Effects of Anisotropy on Pair-wise Entanglement of a Four-Qubit Heisenberg[J]. 中国物理快报, 2006, 23(11): 2888-2891.
CAO Min, ZHU Shi-Qun. Effects of Anisotropy on Pair-wise Entanglement of a Four-Qubit Heisenberg. Chin. Phys. Lett., 2006, 23(11): 2888-2891.
2006, Vol. 23 
