中国物理B ›› 2025, Vol. 34 ›› Issue (8): 80501-080501.doi: 10.1088/1674-1056/add50f

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Thermodynamics of classical one-dimensional generalized nonlinear Klein-Gordon lattice model

Hu-Wei Jia(贾虎伟)1,2 and Ning-Hua Tong(同宁华)1,2,†   

  1. 1 School of Physics, Renmin University of China, Beijing 100872, China;
    2 Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, China
  • 收稿日期:2025-04-15 修回日期:2025-05-02 接受日期:2025-05-07 出版日期:2025-07-17 发布日期:2025-08-08
  • 通讯作者: Ning-Hua Tong E-mail:nhtong@ruc.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11974420).

Thermodynamics of classical one-dimensional generalized nonlinear Klein-Gordon lattice model

Hu-Wei Jia(贾虎伟)1,2 and Ning-Hua Tong(同宁华)1,2,†   

  1. 1 School of Physics, Renmin University of China, Beijing 100872, China;
    2 Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, China
  • Received:2025-04-15 Revised:2025-05-02 Accepted:2025-05-07 Online:2025-07-17 Published:2025-08-08
  • Contact: Ning-Hua Tong E-mail:nhtong@ruc.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11974420).

摘要: We study the thermodynamic properties of the classical one-dimensional generalized nonlinear Klein-Gordon lattice model ($n \ge 2$) by using the cluster variation method with linear response theory. The results of this method are exact in the thermodynamic limit. We present the single-site reduced density $\rho^{(1)}(z)$, averages such as $\langle z^2 \rangle$, $\langle |z^n|\rangle$, and $\langle (z_1-z_2)^2\rangle$, the specific heat $C_{\rm v}$, and the static correlation functions. We analyze the scaling behavior of these quantities and obtain the exact scaling powers at the low and high temperatures. Using these results, we gauge the accuracy of the projective truncation approximation for the $\phi^{4}$ lattice model.

关键词: cluster variation method, linear response theory, one-dimensional generalized nonlinear Klein-Gordon lattice model

Abstract: We study the thermodynamic properties of the classical one-dimensional generalized nonlinear Klein-Gordon lattice model ($n \ge 2$) by using the cluster variation method with linear response theory. The results of this method are exact in the thermodynamic limit. We present the single-site reduced density $\rho^{(1)}(z)$, averages such as $\langle z^2 \rangle$, $\langle |z^n|\rangle$, and $\langle (z_1-z_2)^2\rangle$, the specific heat $C_{\rm v}$, and the static correlation functions. We analyze the scaling behavior of these quantities and obtain the exact scaling powers at the low and high temperatures. Using these results, we gauge the accuracy of the projective truncation approximation for the $\phi^{4}$ lattice model.

Key words: cluster variation method, linear response theory, one-dimensional generalized nonlinear Klein-Gordon lattice model

中图分类号:  (Classical ensemble theory)

  • 05.20.Gg
05.10.-a (Computational methods in statistical physics and nonlinear dynamics) 05.50.+q (Lattice theory and statistics) 05.70.-a (Thermodynamics)