Optical and electrical feedback cooling of a silica nanoparticle levitated in a Paul trap

TL;DR

This paper demonstrates cooling of a silica nanoparticle's motional modes in a Paul trap using both optical and electrical feedback methods, achieving temperatures of a few millikelvin and analyzing their efficiencies.

Contribution

It introduces and compares optical and electrical feedback cooling techniques for levitated nanoparticles in a Paul trap, showing similar efficiencies for both methods.

Findings

Both feedback methods achieve similar cooling efficiencies.

Cooling performance depends on feedback parameters and background pressure.

Motional modes are cooled to a few millikelvin.

Abstract

All three motional modes of a charged dielectric nanoparticle in a Paul trap are cooled by direct feedback to temperatures of a few mK. We test two methods, one based on electrical forces and the other on optical forces; for both methods, we find similar cooling efficiencies. Cooling is characterized for both feedback forces as a function of feedback parameters, background pressure, and the particle's position.