中国物理B ›› 2025, Vol. 34 ›› Issue (5): 50309-050309.doi: 10.1088/1674-1056/adca16

所属专题: SPECIAL TOPIC — Quantum communication and quantum network

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Dynamics of quantum discord and geometric quantum discord in multiqubit interacting system

Xiao-Di Cheng(程晓迪), Ya-Jun Zheng(郑雅君), Meng-Jie Ran(冉梦杰), and Xiao-Yun Wang(王小云)†   

  1. College of Physics Mechanical and Electrical Engineering, Jishou University, Jishou 416000, China
  • 收稿日期:2024-11-21 修回日期:2025-04-06 接受日期:2025-04-08 出版日期:2025-05-15 发布日期:2025-04-28
  • 通讯作者: Xiao-Yun Wang E-mail:wxyyun@163.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11564013 and 11964010), the Natural Science Foundation of Hunan Province (Grant No. 2020JJ4495), and the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 22A0377 and 21A0333).

Dynamics of quantum discord and geometric quantum discord in multiqubit interacting system

Xiao-Di Cheng(程晓迪), Ya-Jun Zheng(郑雅君), Meng-Jie Ran(冉梦杰), and Xiao-Yun Wang(王小云)†   

  1. College of Physics Mechanical and Electrical Engineering, Jishou University, Jishou 416000, China
  • Received:2024-11-21 Revised:2025-04-06 Accepted:2025-04-08 Online:2025-05-15 Published:2025-04-28
  • Contact: Xiao-Yun Wang E-mail:wxyyun@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11564013 and 11964010), the Natural Science Foundation of Hunan Province (Grant No. 2020JJ4495), and the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 22A0377 and 21A0333).

摘要: Using quantum discord (QD) and geometric quantum discord (GQD), quantum correlation dynamics is investigated for two coupled qubits within a multiqubit interacting system in the zero-temperature bosonic reservoir, under both weak and strong qubit-reservoir coupling regimes. The multiqubit system is connected with either a common bosonic reservoir (CBR) or multiple independent bosonic reservoirs (IBRs). In the CBR case, our findings indicate that both QD and GQD can be strengthened by increasing the number of qubits in the multiqubit system. Furthermore, we study the steady state QD and GQD in the strong coupling regime, and find that the stable value in the long-time limit is determined exclusively by the number of qubits. The evolution period of QD and GQD gets longer as the dipole-dipole interaction (DDI) strength increases, which helps prolong the correlation time and thus preserves the quantum correlation under the weak coupling regime. Further analysis reveals notable differences between the CBR and IBRs scenarios. In the IBRs case, the decay of QD and GQD becomes slower compared to the CBR case, with both measures tending to zero at a reduced rate. Moreover, GQD consistently exhibits lower values than QD in both scenarios. These findings provide valuable insights into the selection of appropriate correlation measurement techniques for quantifying quantum correlations.

关键词: quantum discord, geometric quantum discord, quantum correlation dynamics, multiqubit system

Abstract: Using quantum discord (QD) and geometric quantum discord (GQD), quantum correlation dynamics is investigated for two coupled qubits within a multiqubit interacting system in the zero-temperature bosonic reservoir, under both weak and strong qubit-reservoir coupling regimes. The multiqubit system is connected with either a common bosonic reservoir (CBR) or multiple independent bosonic reservoirs (IBRs). In the CBR case, our findings indicate that both QD and GQD can be strengthened by increasing the number of qubits in the multiqubit system. Furthermore, we study the steady state QD and GQD in the strong coupling regime, and find that the stable value in the long-time limit is determined exclusively by the number of qubits. The evolution period of QD and GQD gets longer as the dipole-dipole interaction (DDI) strength increases, which helps prolong the correlation time and thus preserves the quantum correlation under the weak coupling regime. Further analysis reveals notable differences between the CBR and IBRs scenarios. In the IBRs case, the decay of QD and GQD becomes slower compared to the CBR case, with both measures tending to zero at a reduced rate. Moreover, GQD consistently exhibits lower values than QD in both scenarios. These findings provide valuable insights into the selection of appropriate correlation measurement techniques for quantifying quantum correlations.

Key words: quantum discord, geometric quantum discord, quantum correlation dynamics, multiqubit system

中图分类号:  (Foundations of quantum mechanics; measurement theory)

  • 03.65.Ta
03.65.Yz (Decoherence; open systems; quantum statistical methods) 03.67.Pp (Quantum error correction and other methods for protection against decoherence)