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Open AccessArticle
The Finite-Temperature Casimir Effect in a One-Dimensional Scalar Field with Two Delta-Function Potentials
by
Xu-Feng Zhao
Xu-Feng Zhao 1,2,
Shao-Zhe Lu
Shao-Zhe Lu 1,2,
Rong-Sheng Han
Rong-Sheng Han 1,2 and
Liang Chen
Liang Chen 1,2,3,*
1
School of Mathematics and Physics, North China Electric Power University, Beijing 102206, China
2
Institute of Condensed Matter Physics, North China Electric Power University, Beijing 102206, China
3
Hebei Key Laboratory of Physics and Energy Technology, North China Electric Power University, Baoding 071003, China
*
Author to whom correspondence should be addressed.
Appl. Sci. 2026, 16(11), 5246; https://doi.org/10.3390/app16115246 (registering DOI)
Submission received: 12 April 2026
/
Revised: 15 May 2026
/
Accepted: 20 May 2026
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Published: 23 May 2026
Abstract
We investigate the finite-temperature Casimir interaction between two delta-function potentials in a -dimensional scalar field model using Lifshitz theory, canonical quantization, and the Green’s function method. The Casimir force computed from all three approaches is in complete agreement. The Casimir entropy is also broadly consistent across the three methods, with subtle differences that can be traced to the infrared logarithmic divergence in the free energy. This divergence originates from the zero-frequency term and affects the entropy but not the force. In the Lifshitz approach, regularization requires an external infrared cutoff; in canonical quantization and the Green’s function method, the cutoff is naturally related to the finite size of the physical system.
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MDPI and ACS Style
Zhao, X.-F.; Lu, S.-Z.; Han, R.-S.; Chen, L.
The Finite-Temperature Casimir Effect in a One-Dimensional Scalar Field with Two Delta-Function Potentials. Appl. Sci. 2026, 16, 5246.
https://doi.org/10.3390/app16115246
AMA Style
Zhao X-F, Lu S-Z, Han R-S, Chen L.
The Finite-Temperature Casimir Effect in a One-Dimensional Scalar Field with Two Delta-Function Potentials. Applied Sciences. 2026; 16(11):5246.
https://doi.org/10.3390/app16115246
Chicago/Turabian Style
Zhao, Xu-Feng, Shao-Zhe Lu, Rong-Sheng Han, and Liang Chen.
2026. "The Finite-Temperature Casimir Effect in a One-Dimensional Scalar Field with Two Delta-Function Potentials" Applied Sciences 16, no. 11: 5246.
https://doi.org/10.3390/app16115246
APA Style
Zhao, X.-F., Lu, S.-Z., Han, R.-S., & Chen, L.
(2026). The Finite-Temperature Casimir Effect in a One-Dimensional Scalar Field with Two Delta-Function Potentials. Applied Sciences, 16(11), 5246.
https://doi.org/10.3390/app16115246
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