中国物理B ›› 2016, Vol. 25 ›› Issue (3): 30303-030303.doi: 10.1088/1674-1056/25/3/030303

• GENERAL • 上一篇    下一篇

Entanglement detection in the mixed-spin Ising-XY model

Hamid Arian Zad   

  1. Department of Physics, Shahrood University of Technology, Shahrood 36155-316, Iran
  • 收稿日期:2015-10-29 修回日期:2015-12-02 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: Hamid Arian Zad E-mail:arianzad.hamid@yahoo.com

Entanglement detection in the mixed-spin Ising-XY model

Hamid Arian Zad   

  1. Department of Physics, Shahrood University of Technology, Shahrood 36155-316, Iran
  • Received:2015-10-29 Revised:2015-12-02 Online:2016-03-05 Published:2016-03-05
  • Contact: Hamid Arian Zad E-mail:arianzad.hamid@yahoo.com

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 γ 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. Finally, 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

Abstract:

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 γ 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. Finally, some new interesting entanglement witnesses are introduced by using non-degenerate perturbation theory for the mixed-three-spin system.

Key words: anisotropy, negativity, heat capacity, witness

中图分类号:  (Entanglement measures, witnesses, and other characterizations)

  • 03.67.Mn
03.65.Aa (Quantum systems with finite Hilbert space) 64.60.De (Statistical mechanics of model systems (Ising model, Potts model, field-theory models, Monte Carlo techniques, etc.)) 05.30.Rt (Quantum phase transitions)