Casimir Force and In Situ Surface Potential Measurements on Nanomembranes

TL;DR

This study accurately measures the Casimir force between a nanomembrane and a sphere in the 100 nm to 2 μm range, using high-resolution resonance techniques and surface potential imaging to improve precision.

Contribution

It introduces a high-resolution resonance method combined with in situ surface potential imaging for precise Casimir force measurements on nanomembranes.

Findings

Casimir force measured from 100 nm to 2 μm range

Device data aligns with the Drude model

Achieved force gradient sensitivity of 3 μN/m

Abstract

We present Casimir force measurements in a sphere-plate configuration that consists of a high quality nanomembrane resonator and a millimeter sized gold coated sphere. The nanomembrane is fabricated from stoichiometric silicon nitride metallized with gold. A Kelvin probe method is used in situ to image the surface potentials to minimize the distance-dependent residual force. Resonance-enhanced frequency-domain measurements of the nanomembrane motion allow for very high resolution measurements of the Casimir force gradient (down to a force gradient sensitivity of 3 uN/m). Using this technique, the Casimir force in the range of 100 nm to 2 um is accurately measured. Experimental data thus obtained indicate that the device system in the measured range is best described with the Drude model.