Quantum phase transition and entanglement in Heisenberg XX spin chain with impurity  

作　　者：陈士荣 夏云杰 满忠晓 

机构地区：[1]Shandong Provincial Key Laboratory of Laser Polarization and Information Technology,Department of Physics,Qufu Normal University

出　　处：《Chinese Physics B》2010年第5期48-57,共10页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No. 10774088);the Key Program of the National Natural Science Foundation of China (Grant No. 10534030)

摘　　要：In this paper, we study the quantum phase transition and the effect of impurity on the thermal entanglement between any two lattices in three-qubit Heisenberg XX chain in a uniform magnetic field. We show that the quantum phase transition always appears when impurity parameter is an arbitrary constant and unequal to zero, the external magnetic field and impurity parameters have a great effect on it. Also, there exists a relation between the quantum phase transition and the entanglement. By modulating the temperature, magnetic field and the impurity parameters, the entanglement between any two lattices can exhibit platform-like behaviour, which can be used to realize entanglement switch.In this paper, we study the quantum phase transition and the effect of impurity on the thermal entanglement between any two lattices in three-qubit Heisenberg XX chain in a uniform magnetic field. We show that the quantum phase transition always appears when impurity parameter is an arbitrary constant and unequal to zero, the external magnetic field and impurity parameters have a great effect on it. Also, there exists a relation between the quantum phase transition and the entanglement. By modulating the temperature, magnetic field and the impurity parameters, the entanglement between any two lattices can exhibit platform-like behaviour, which can be used to realize entanglement switch.

关 键 词：Heisenberg XX chain thermal entanglement impurity lattice quantum phase transition 

分 类 号：O413.1[理学—理论物理] TN304.12[理学—物理]