Precision and Casimir Force Measurements in Superfluid and Vacuum with Silicon Nitride Membranes

TL;DR

This paper explores the use of silicon nitride membranes as high-Q resonators for precise measurements of Casimir forces in vacuum and superfluid helium, enabling new experimental possibilities.

Contribution

It demonstrates the potential of silicon nitride membranes for advanced force measurements and proposes measuring the phonon analog of the Casimir force in liquid helium.

Findings

Silicon nitride membranes enable high-precision force measurements.

Thermal corrections to Casimir force depend only on temperature and distance.

Proposal to measure phonon Casimir force in superfluid helium.

Abstract

The recent discovery that silicon nitride membranes can be used as extremely high Q mechanical resonators makes possible a number of novel experiments, which include improved long range vacuum Casimir force measurements, and measurments of the properties of liquid helium below the lambda point. It is noted that in the thermal correction to the Casimir force, the phase velocity of the excitations does not enter, with the force per unit area between parallel plates depending only on the temperature and distance between the plates. Thus it appears as possible to measure the phonon analog of the finite temperature Casimir force in liquid helium.