原子与分子物理学报2007，Vol.24Issue(6)：1309-1315,7.
非匀强磁场中双量子位Heisenberg XY链的基态纠缠和热纠缠
Thermal and ground-state entanglement in the two-qubit anisotropic Heisenberg XY spin chain under an inhomogeneous magnetic field
摘要
Abstract
We study the entanglement of thermal and ground states in the Heisenberg XY spin chain with an inhomogeneous magnetic field. A general result is found that for two-qubit case, pairwise entanglement is independent of the sign of coupling constant J, magnetic field B, anisotropic parameter γ and inhomogeneous parameter b of the magnetic field. At zero absolute temperature, an analytical expression of concurrence C is given through which we show that the critical magnetic field Bc increases with the increase of inhomogeneity.At finite temperature, we show analytically for the isotropic case and numerically for the anisotropic case that the thermal entanglement can be apparently enhanced by introducing the inhomogeneity of the magnetic field.We also show that for isotropie case the critical temperature Tc is alone an increasing function of the inhomogeneous parameter b, while for anisotropic case, it is determined by both B and b.关键词
Heisenberg XY链/热纠缠Key words
Heisenberg XY chain/ thermal entanglement分类
数理科学引用本文复制引用
胡明亮,田东平..非匀强磁场中双量子位Heisenberg XY链的基态纠缠和热纠缠[J].原子与分子物理学报,2007,24(6):1309-1315,7.基金项目
陕西省2004年自然科学研究计划(2004A15) （2004A15）
