Trap-to-trap free falls with an optically levitated nanoparticle
Phys. Rev. A 113, 023510 – Published 9 February, 2026
DOI: https://doi.org/10.1103/47pz-74fc
Abstract
We perform free-fall experiments with a charge-neutral, optically levitated nanoparticle. This is achieved using an optical tweezer that can be rapidly toggled on and off and vertically displaced, enabling the particle to be released and recaptured after each free fall. The particle is insensitive to electric fields due to its charge neutrality, and during free evolution, is not subject to photon recoil heating. We achieve free-fall durations of up to and observe a nearly 200-fold increase in the particle's position uncertainty at recapture. The current limit on the free-fall time arises from the performance of the initial cooling step. By implementing linear feedback techniques and reducing the background pressure, we expect to perform millisecond-scale free-fall experiments in an ultrahigh vacuum, opening new opportunities for generating large delocalizations of levitated objects.
