Entanglement detection in the mixed-spin Ising–XY model  

作　　者：Hamid Arian Zad 

机构地区：[1]Department of Physics, Shahrood University of Technology

出　　处：《Chinese Physics B》2016年第3期73-83,共11页中国物理B（英文版）

摘　　要：In the present work, we initially verify anisotropy effect on the heat capacity of a mixed-three-spin （1/2,1,1/2） system （where spins （1/2,1/2） have XY interaction and spins （1,1/2） have Ising interaction together） at finite temperatures, then, the pairwise entanglement for spins （1/2,1/2）, by means of negativity （as a measure of entanglement） as a function of the temperature T, homogeneous magnetic field B, and anisotropy parameter 7 is investigated. In addition, we show that one can find magnetic phase transition points for the spins （1/2,1/2） at finite temperatures and understand properly their behavior with respect to the magnetic field and the anisotropy parameter, via the negativity function. An interval of the magnetic field from the negativity diagram of the spins （1/2,1/2） is presented in which quantum phase transition occurs for the tripartite mixed-three-spin system. FinaUy, some new interesting entanglement witnesses are introduced by using non-degenerate perturbation theory for the mixed-three-spin system.In the present work, we initially verify anisotropy effect on the heat capacity of a mixed-three-spin （1/2,1,1/2） system （where spins （1/2,1/2） have XY interaction and spins （1,1/2） have Ising interaction together） at finite temperatures, then, the pairwise entanglement for spins （1/2,1/2）, by means of negativity （as a measure of entanglement） as a function of the temperature T, homogeneous magnetic field B, and anisotropy parameter 7 is investigated. In addition, we show that one can find magnetic phase transition points for the spins （1/2,1/2） at finite temperatures and understand properly their behavior with respect to the magnetic field and the anisotropy parameter, via the negativity function. An interval of the magnetic field from the negativity diagram of the spins （1/2,1/2） is presented in which quantum phase transition occurs for the tripartite mixed-three-spin system. FinaUy, some new interesting entanglement witnesses are introduced by using non-degenerate perturbation theory for the mixed-three-spin system.

关 键 词：ANISOTROPY NEGATIVITY heat capacity WITNESS 

分 类 号：O413[理学—理论物理] O41[理学—物理]