摘要
研究时变外磁场对海森堡模型的热力学纠缠.以两量子比特海森堡XX模型为例,得出时变外磁场加在单电子上的纠缠度解析表达式,并在此基础上进行数值计算,讨论温度对系统纠缠的影响.同时,分析在时变外磁场的影响下,纠缠度随时间演化发生周期性震荡的情况,以及时变磁场的磁场强度和关联强度对系统纠缠度的作用,进而通过调节外磁场和关联强度有效控制系统的纠缠.
The analytical express of thermal concurrence is obtained by studying two-qubit XX model with variation of magnetic field on one electron with time,and on this basis,the numerical calculation is performed.The impact of temperature on the system entanglement is discussed.The results show that,as the temperature increases,the value of system entanglement reduces unceasingly,and the entanglement will ultimately completely vanish.The entanglement varies periodically under the time-varying magnetic field.The effects of magnetic field strength and interaction of two neighboring spins on entanglement are examined.By adjusting the magnetic field and the interaction,the system entanglement can be controlled effectively.
出处
《天津师范大学学报（自然科学版）》
CAS
北大核心
2010年第2期43-46,共4页
Journal of Tianjin Normal University：Natural Science Edition
关键词
XX模型
热力学纠缠
时变磁场
XX model
thermal entanglement
time-varying magnetic field
