Li Yang, Milton Kimball A, Parashar Prachi, Hong Lujun
Department of Physics, Nanchang University, Nanchang 330031, China.
Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019, USA.
Entropy (Basel). 2021 Feb 10;23(2):214. doi: 10.3390/e23020214.
It has been recognized for some time that, even for perfect conductors, the interaction Casimir entropy, due to quantum/thermal fluctuations, can be negative. This result was not considered problematic because it was thought that the self-entropies of the bodies would cancel this negative interaction entropy, yielding a total entropy that was positive. In fact, this cancellation seems not to occur. The positive self-entropy of a perfectly conducting sphere does indeed just cancel the negative interaction entropy of a system consisting of a perfectly conducting sphere and plate, but a model with weaker coupling in general possesses a regime where negative self-entropy appears. The physical meaning of this surprising result remains obscure. In this paper, we re-examine these issues, using improved physical and mathematical techniques, partly based on the Abel-Plana formula, and present numerical results for arbitrary temperatures and couplings, which exhibit the same remarkable features.
一段时间以来，人们已经认识到，即使对于理想导体，由于量子/热涨落导致的相互作用卡西米尔熵也可能为负。这个结果当时并未被视为有问题，因为人们认为物体的自熵会抵消这种负的相互作用熵，从而产生正的总熵。事实上，这种抵消似乎并未发生。理想导电球体的正自熵确实恰好抵消了由理想导电球体和平板组成的系统的负相互作用熵，但一般来说，耦合较弱的模型存在出现负自熵的情况。这个惊人结果的物理意义仍然模糊不清。在本文中，我们使用改进的物理和数学技术（部分基于阿贝尔 - 普拉纳公式）重新审视这些问题，并给出任意温度和耦合情况下的数值结果，这些结果展现出相同的显著特征。
