摘要
负值度(Negativity)是一种通用的纠缠度量,可方便地计算两体量子系统的纠缠度.利用负值度研究了两量子比特各向异性海森伯格XXZ模型的热纠缠,讨论了在热平衡时温度和外加磁场对热纠缠的影响.当温度小于临界温度时,热纠缠的大小依赖于外加磁场的强弱;当温度大于临界温度时,纠缠消失.
Negativity is an universal entanglement measure. The entanglement of two-party quantum system can be easily calculated with negativity. The thermal entanglement in the two qubit anisotropic Heisenberg XXZ model is studies by means of Negativity. The influence of temperature Tand an external magnetic field B on the entanglement is investigated in thermal equilibrium. When the temperature is less than an critical temperature Tc, the thermal entanglement is depended on the magnetic field strength, otherwise the entanglement disappears.
出处
《江汉大学学报(自然科学版)》
2009年第3期33-35,39,共4页
Journal of Jianghan University:Natural Science Edition
关键词
海森伯格模型
负值度
热纠缠
Heisenbergmodel
negativity
thermal entanglement
anisotropy