Comment on "Anomalous temperature dependence of the Casimir force for thin metal films" [arXiv:0712.1395]

TL;DR

This paper refutes a recent claim that the Casimir force decreases with temperature for thin metal films, showing instead that for bulk samples described by the Drude model, the force actually decreases significantly with temperature, contradicting experimental observations.

Contribution

The paper clarifies the temperature dependence of the Casimir force for bulk samples versus thin films, correcting previous theoretical claims and aligning with experimental data.

Findings

Casimir force decreases with temperature in bulk samples described by the Drude model

The magnitude of this decrease is larger than that for thin films

Experimental data already exclude the predicted decrease for thin films

Abstract

Recently V. A. Yampol'skii, S. Savel'ev, Z. A. Mayselis, S. S. Apostolov, and F. Nori [Phys. Rev. Lett., v.101, 096803 (2008),arXiv:0712.1395] claimed that the Casimir force between a thin metal film described by the Drude model and an ideal metal semispace can decrease with temperature whereas for bulk samples the Casimir force increases with temperature. On this basis the experimental observation of the decreasing temperature dependence of the Casimir force magnitude between a film and a bulk ideal metal was proposed. We demonstrate that, contrary to what is claimed by the authors, the magnitude of the Casimir force decreases with temperature in a wide temperature region for bulk samples described by the Drude model. This decrease is shown to be much larger than that for a thin film and it has already been experimentally excluded.