中国物理B ›› 2014, Vol. 23 ›› Issue (5): 50305-050305.doi: 10.1088/1674-1056/23/5/050305

• GENERAL • 上一篇    下一篇

Thermal entanglement in the mixed three-spin XXZ Heisenberg model on a triangular cell

Seyit Deniz Han, Ekrem Aydiner   

  1. Department of Physics, İstanbul University, İstanbul Tr-34134, Turkey
  • 收稿日期:2013-07-30 修回日期:2013-10-18 出版日期:2014-05-15 发布日期:2014-05-15
  • 基金资助:
    Project supported by ?stanbul University (Grant Nos. 19240 and 28432).

Thermal entanglement in the mixed three-spin XXZ Heisenberg model on a triangular cell

Seyit Deniz Han, Ekrem Aydiner   

  1. Department of Physics, īstanbul University, īstanbul Tr-34134, Turkey
  • Received:2013-07-30 Revised:2013-10-18 Online:2014-05-15 Published:2014-05-15
  • Contact: Ekrem Aydiner E-mail:ekrem.aydiner@istanbul.edu.tr
  • About author:03.65.Ud; 64.70.Tg
  • Supported by:
    Project supported by īstanbul University (Grant Nos. 19240 and 28432).

摘要: We numerically investigate the thermal entanglements of spins (1/2, 1) and spins (1/2, 1/2) in the three-mixed (1/2, 1, 1/2) anisotropic Heisenberg XXZ spin system on a simple triangular cell under an inhomogeneous magnetic field. We show that the external magnetic field induces strong plateau formation in the pairwise thermal entanglement for fixed parameters of the Hamiltonian in the cases of ferromagnetic and antiferromagnetic interactions. We also observe an unexpected critical point at finite temperature in the thermal entanglement of spins (1/2, 1) for the antiferromagnetic case, while the entanglement of spins (1/2, 1) in the ferromagnetic case and the entanglement of spins (1/2, 1/2) in both ferromagnetic and antiferromagnetic cases almost decay exponentially to zero with increasing temperature. The critical point in the entanglement of spins (1/2, 1) in the antiferromagnetic case may be a signature of the quantum phase transition at finite temperature.

关键词: quantum entanglement, quantum phase transition, negativity

Abstract: We numerically investigate the thermal entanglements of spins (1/2, 1) and spins (1/2, 1/2) in the three-mixed (1/2, 1, 1/2) anisotropic Heisenberg XXZ spin system on a simple triangular cell under an inhomogeneous magnetic field. We show that the external magnetic field induces strong plateau formation in the pairwise thermal entanglement for fixed parameters of the Hamiltonian in the cases of ferromagnetic and antiferromagnetic interactions. We also observe an unexpected critical point at finite temperature in the thermal entanglement of spins (1/2, 1) for the antiferromagnetic case, while the entanglement of spins (1/2, 1) in the ferromagnetic case and the entanglement of spins (1/2, 1/2) in both ferromagnetic and antiferromagnetic cases almost decay exponentially to zero with increasing temperature. The critical point in the entanglement of spins (1/2, 1) in the antiferromagnetic case may be a signature of the quantum phase transition at finite temperature.

Key words: quantum entanglement, quantum phase transition, negativity

中图分类号:  (Entanglement and quantum nonlocality)

  • 03.65.Ud
64.70.Tg (Quantum phase transitions)