Force-Gradient Sensing and Entanglement via Feedback Cooling of Interacting Nanoparticles

TL;DR

This paper demonstrates theoretically that feedback cooling of interacting nanoparticles can enable sensitive force-gradient detection and generate observable stationary entanglement, advancing quantum sensing and entanglement studies.

Contribution

It introduces a method for using feedback cooling to achieve differential force sensing and stationary entanglement in levitated nanoparticles, a novel approach in quantum sensing.

Findings

Force-gradient sensing at the zepto-Newton per micron level is feasible.

Stationary entanglement can be observed with strong inter-particle Coulomb coupling.

Feedback cooling creates a non-thermal state sensitive to force inhomogeneities.

Abstract

We show theoretically that feedback-cooling of two levitated, interacting nanoparticles enables differential sensing of forces and the observation of stationary entanglement. The feedback drives the two particles into a stationary, non-thermal state which is susceptible to inhomogeneous force fields and which exhibits entanglement for sufficiently strong inter-particle couplings. We predict that force-gradient sensing at the zepto-Newton per micron range is feasible and that entanglement due to the Coulomb interaction between charged particles can be realistically observed in state-of-the-art setups.