Observing the Casimir-Lifshitz Force Out of Thermal Equilibrium

TL;DR

This paper proposes an experimental setup to observe the thermal Casimir-Lifshitz force out of thermal equilibrium between two macroscopic bodies at submicron separations, overcoming previous measurement challenges.

Contribution

It introduces a novel apparatus enabling direct measurement of the thermal Casimir-Lifshitz force out of equilibrium at moderate temperature differences.

Findings

Design of an experimental setup for observing the out-of-equilibrium thermal force.

Feasibility of measuring the thermal Casimir-Lifshitz force at submicron separations.

Potential to explore new physical phenomena in non-equilibrium quantum forces.

Abstract

The thermal Casimir-Lifshitz force among two bodies held at different temperatures displays striking features that are absent in systems in thermal equilibrium. The manifestation of this force has been observed so far only in Bose-Einstein condensates close to a heated substrate, but never between two macroscopic bodies. Observation of the thermal Casimir-Lifhitz force out of thermal equilibrium with conventional Casimir setups is very difficult, because for experimentally accessible separations the thermal force is small compared to the zero-temperature quantum Casimir force, unless prohibitively large temperature differences among the plates are considered. We describe an apparatus that allows for a direct observation of the thermal force out of equilibrium for submicron separations and for moderate temperature differences between the plates.