中国物理B ›› 2010, Vol. 19 ›› Issue (10): 100307-100307.doi: 10.1088/1674-1056/19/10/100307

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Pairwise thermal entanglement in a three-qubit Heisenberg XX model with a nonuniform magnetic field and Dzyaloshinski–Moriya interaction

Yeon Kyu-Hwang1, 邵晓强2, 任金忠3, 张寿3   

  1. (1)BK21 Program Physics and Department of Physics, College of Natural Science, Chungbuk National University, Cheonju, Chungbuk 361-763, Republic of Korea; (2)Center for the Condensed-Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150001, China; (3)Department of Physics, College of Science, Yanbian University, Yanji 133002, Jilin Province, China
  • 收稿日期:2010-01-26 修回日期:2010-04-14 出版日期:2010-10-15 发布日期:2010-10-15

Pairwise thermal entanglement in a three-qubit Heisenberg XX model with a nonuniform magnetic field and Dzyaloshinski–Moriya interaction

Ren Jin-Zhong(任金忠)a), Shao Xiao-Qiang(邵晓强)b), Zhang Shou(张寿)a)†, and Yeon Kyu-Hwangc)   

  1. a Department of Physics, College of Science, Yanbian University, Yanji 133002, Jilin Province, China; b Center for the Condensed-Matter Science and Technology, Department of Physics, Harbin Institute of Technology, Harbin 150001, China; c BK21 Program Physics and Department of Physics, College of Natural Science, Chungbuk National University, Cheonju, Chungbuk 361-763, Republic of Korea
  • Received:2010-01-26 Revised:2010-04-14 Online:2010-10-15 Published:2010-10-15

摘要: Pairwise thermal entanglement in a three-qubit Heisenberg XX model is investigated when a nonuniform magnetic field and the Dzyaloshinski--Moriya interaction are included. We find that the nonuniform magnetic field and Dzyaloshinski--Moriya interaction are the more efficient control parameters for the increase of entanglement and critical temperature. For both the nearest neighbour sites and the next nearest neighbour sites, the magnetic field can induce entanglement to a certain extent and the Dzyaloshinski--Moriya interaction can enhance the entanglement to a stable value. The steady value of the nearest neighbour site entanglement C12 is larger than the next nearest neighbour site entanglement C13. An interesting phenomenon is that the entanglement curve of C12 appears a peak value when the Dzyaloshinski--Moriya interaction is considered in a nonuniform magnetic field.

Abstract: Pairwise thermal entanglement in a three-qubit Heisenberg XX model is investigated when a nonuniform magnetic field and the Dzyaloshinski–Moriya interaction are included. We find that the nonuniform magnetic field and Dzyaloshinski–Moriya interaction are the more efficient control parameters for the increase of entanglement and critical temperature. For both the nearest neighbour sites and the next nearest neighbour sites, the magnetic field can induce entanglement to a certain extent and the Dzyaloshinski–Moriya interaction can enhance the entanglement to a stable value. The steady value of the nearest neighbour site entanglement C12 is larger than the next nearest neighbour site entanglement C13. An interesting phenomenon is that the entanglement curve of C12 appears a peak value when the Dzyaloshinski–Moriya interaction is considered in a nonuniform magnetic field.

Key words: thermal entanglement, nonuniform magnetic field, Dzyaloshinski–Moriya interaction, Heisenberg model

中图分类号:  (Entanglement and quantum nonlocality)

  • 03.65.Ud
03.67.Lx (Quantum computation architectures and implementations) 03.67.Mn (Entanglement measures, witnesses, and other characterizations) 75.10.Jm (Quantized spin models, including quantum spin frustration) 75.30.Et (Exchange and superexchange interactions)