On the entropy of a spherical plasma shell

Abstract

Negative entropy was repeatedly observed in the Casimir effect caused by dissipation or geometry. However, it was restricted to subsystems. Recently the question about the entropy for a complete Casimir effect like configuration was raised. In the present paper we consider a spherical plasma shell which can be considered as a (crude) model for a giant carbon molecule (e.g., $C_{60}$). The entropy is free of ultraviolet divergences and its calculation does not need any regularization. We calculate the entropy numerically and demonstrate unambiguously the existence of a region where it takes negative values. This region is at small values of temperature and plasma frequency (in units of the radius).

13 pages, 2 figures, some misprints corrected, several improvements

References in corpus (7)

• Thermal corrections to the Casimir effect
• Thermal Casimir effect in ideal metal rectangular boxes
• On the vacuum energy of a spherical plasma shell
• Casimir Self-Entropy of a Spherical Electromagnetic $\delta$-Function Shell
• Casimir and Casimir-Polder forces with dissipation from first principles
• Casimir Self-Entropy of an Electromagnetic Thin Sheet
• Presence of negative entropies in Casimir interactions

Cited by in corpus (7)

• Free energy and entropy for thin sheets
• Remarks on the Casimir Self-Entropy of a Spherical Electromagnetic $\delta$-Function Shell
• Thermal Casimir effect with general boundary conditions
• Free energy and entropy for finite temperature quantum field theory under the influence of periodic backgrounds
• Negativity of the Casimir self-entropy in spherical geometries
• Casimir Self-Entropy of Nanoparticles with Classical Polarizabilities: Electromagnetic Field Fluctuations
• Casimir effect for scalar field rotating on a disk