Mechanism underlying electric stray-field fluctuations causing shot-to-shot force noise

Ascertain whether the observed agreement between the standard deviation σ_f0 of shot-to-shot constant force noise inferred in optically levitated charged‑nanoparticle experiments that use frequency‑jump state manipulations and the force fluctuations measured in independent levitated‑optomechanics experiments employing inverted potentials indicates a common underlying mechanism responsible for generating electric stray‑field fluctuations that act on the particle from shot to shot.

Background

In the experimental demonstration, the authors quantify shot-to-shot force noise f0 arising from slowly varying stray electric fields acting on the charge of an optically levitated nanoparticle. They extract the standard deviation σ_f0 from covariance measurements during their oscillator-echo protocol and find values consistent with those observed in an independent setup involving state-expansion protocols with inverted potentials.

This numerical agreement prompts the authors to raise an explicit open question about whether the concordance reveals a common physical origin for the stray-field fluctuations. Resolving this would clarify the mechanism producing electric stray-field noise in levitated optomechanics, which is crucial for future protocols aiming at highly pure squeezed or non-Gaussian motional states of charged particles.