Direct measurement of short-range forces with a levitated nanoparticle

TL;DR

This paper demonstrates a novel experimental approach using levitated nanoparticles to directly measure short-range forces with unprecedented sensitivity and distance range, addressing longstanding challenges in the field.

Contribution

The study introduces a new levitation-based method for direct measurement of short-range forces, surpassing previous force microscopy techniques in sensitivity and distance range.

Findings

Achieved direct measurement of short-range forces near a silicon surface.

Outperformed existing force microscopies in sensitivity and distance.

Provided new insights into nanoscale force interactions.

Abstract

Short-range forces have important real-world relevance across a range of settings in the nano world, from colloids and possibly for protein folding to nano-mechanical devices, but also for detection of weak long-range forces, such as gravity, at short distances and of candidates to solve the problem of dark energy. Short-range forces, such as Casimir-Polder or van der Waals are in general difficult to calculate as a consequence of their non-additive nature, and challenging to measure due to their small magnitude - especially for charged particles where dispersion forces are normally many orders of magnitude smaller than electrostatic image forces. Therefore short-range forces have represented a continuing theoretical and experimental challenge over the last half-century. Here we report on experiments with a single glass nanoparticle levitated in close proximity to a neutral silicon surface in vacuum, which allow for direct measurement of short-range forces in a new distance and sensitivity regime - outperforming existing force microscopies.