Abstract
Interferometric methods for detecting the motion of a levitated nanoparticle provide a route to the quantum ground state, but such methods are currently limited by mode mismatch between the reference beam and the dipolar field scattered by the particle. Here we demonstrate a self-interference method to detect the particle’s motion that solves this problem. A Paul trap confines a charged dielectric nanoparticle in high vacuum, and a mirror retro-reflects the scattered light. We measure the particle’s motion with a sensitivity of , corresponding to a detection efficiency of 2.1%, with a numerical aperture of 0.18. As an application of this method, we cool the particle, via feedback, to temperatures below those achieved in the same setup using a standard position measurement.
- Received 3 January 2022
- Accepted 20 May 2022
DOI:https://doi.org/10.1103/PhysRevLett.129.013601
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
synopsis
Mirror Image Pinpoints a Nanoparticle’s Position
Published 28 June 2022
A scattered laser beam’s interaction with itself creates a motion-detection method precise enough to determine whether a trapped particle is in its ground state.
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