Casimir interaction from magnetically coupled eddy currents

TL;DR

This paper investigates how eddy currents in metallic plates contribute to the Casimir interaction, revealing a crossover from quantum to thermal regimes and explaining thermal anomalies and entropy behavior.

Contribution

It introduces a physical model of eddy current modes as the main contributors to Casimir forces and thermal anomalies in good conductors.

Findings

Eddy current modes cause a crossover from quantum to thermal regimes.

These modes explain the thermal anomalies of the Casimir effect.

The Casimir entropy at zero temperature is linked to a correlated, glassy state.

Abstract

We study the quantum and thermal fluctuations of eddy (Foucault) currents in thick metallic plates. A Casimir interaction between two plates arises from the coupling via quasi-static magnetic fields. As a function of distance, the relevant eddy current modes cross over from a quantum to a thermal regime. These modes alone reproduce previously discussed thermal anomalies of the electromagnetic Casimir interaction between good conductors. In particular, they provide a physical picture for the Casimir entropy whose nonzero value at zero temperature arises from a correlated, glassy state.