Perturbative nonlinear feedback forces for optical levitation experiments

TL;DR

This paper explores how feedback control can create nonlinear potentials in optical traps, specifically a quartic potential, and verifies theoretical predictions experimentally, advancing control of mechanical motion at the nanoscale.

Contribution

It introduces a method to generate and analyze a feedback-induced quartic potential on a levitated nanoparticle, including effects of feedback delay, with experimental validation.

Findings

Feedback delay impacts nonlinear potential formation.

Perturbation theory accurately predicts nanoparticle behavior.

Experimental results confirm theoretical models.

Abstract

Feedback control can be used to generate well-determined nonlinear effective potentials in an optical trap, a goal whose applications may range from non-equilibrium thermodynamics to the generation of non-Gaussian states of mechanical motion. Here, we investigate the action of an effective feedback-generated quartic potential on a levitated nanoparticle within the perturbation regime. The effects of feedback delay are discussed and predictions from the perturbation theory of a Brownian particle subjected to a quartic anharmonicity are experimentally verified.