Platform for measurements of the Casimir force between two superconductors

TL;DR

This paper introduces an on-chip platform combining optomechanics and superconducting capacitors to measure the Casimir force between superconductors, enabling tests of theoretical predictions near the superconducting transition.

Contribution

It presents a novel experimental platform that overcomes previous alignment challenges to measure Casimir forces between superconductors as they transition into superconductivity.

Findings

Preliminary force measurements demonstrate the device’s capability.

The platform can probe the interplay between Casimir forces and superconductivity.

Potential to test competing theoretical predictions.

Abstract

Several experimental demonstrations of the Casimir force between two closely spaced bodies have been realized over the past two decades. Extending the theory to incorporate the behavior of the force between two superconducting films close to their transition temperature has resulted in competing predictions. To date, no experiment exists that can test these theories, partly due to the difficulty in aligning two superconductors in close proximity, while still allowing for a temperature-independent readout of the arising force between them. Here we present an on-chip platform based on an optomechanical cavity in combination with a grounded superconducting capacitor, which overcomes these challenges and opens up the possibility to probe modifications to the Casimir effect between two closely spaced, freestanding superconductors as they transition into a superconducting state. We also perform preliminary force measurements that demonstrate the capability of these devices to probe the interplay between two widely measured quantum effects: Casimir forces and superconductivity.