Geothermal Casimir Phenomena

TL;DR

This paper investigates how geometry influences the temperature dependence of the Casimir effect, revealing that open geometries exhibit significantly larger thermal corrections than closed ones, especially at room temperature.

Contribution

First analytical and numerical analysis of the interplay between geometry and temperature effects in the Casimir force, highlighting the enhanced thermal sensitivity of open geometries.

Findings

Thermal correction is much larger for open geometries like perpendicular plates.

Closed geometries have a gapped spectrum that suppresses low-temperature thermal excitations.

Open geometries support low-lying thermal modes, leading to stronger temperature dependence.

Abstract

We present first worldline analytical and numerical results for the nontrivial interplay between geometry and temperature dependencies of the Casimir effect. We show that the temperature dependence of the Casimir force can be significantly larger for open geometries (e.g., perpendicular plates) than for closed geometries (e.g., parallel plates). For surface separations in the experimentally relevant range, the thermal correction for the perpendicular-plates configuration exhibits a stronger parameter dependence and exceeds that for parallel plates by an order of magnitude at room temperature. This effect can be attributed to the fact that the fluctuation spectrum for closed geometries is gapped, inhibiting the thermal excitation of modes at low temperatures. By contrast, open geometries support a thermal excitation of the low-lying modes in the gapless spectrum already at low temperatures.