A robust superconducting setup to probe the thermal Casimir effect

TL;DR

This paper proposes a superconducting Casimir apparatus designed to experimentally distinguish between different theoretical models of the thermal Casimir effect, potentially resolving a longstanding debate.

Contribution

It introduces a novel superconducting setup with differential force measurement to unambiguously discriminate between Drude and plasma models of the thermal Casimir effect.

Findings

The setup shows significant force modulation differences depending on the model used.

Differential measurements can clearly distinguish between Drude and plasma predictions.

The design enhances the feasibility of experimental verification of thermal Casimir theories.

Abstract

We describe a superconducting Casimir apparatus inspired by a recently proposed setup involving magnetic surfaces [G. Bimonte, Phys. Rev. Lett. {\bf 112}, 240401 (2014)]. The present setup consists of a superconducting Nb sphere and a flat gold plate including in its interior a superconducting Nb strip. The experimental scheme involves a differential measurement of the Casimir force at a point of the gold plate above the Nb strip and away from from it. We show that similar to the previous setup, the superconducting system considered here implies widely different modulations of the Casimir force, depending on whether the thermal force is computed using the Drude or the plasma model, thus paving the way to an unambiguous discrimination between these alternative prescriptions.