All-optica sub-Kelvin sympathetic cooling of a levitated microsphere in vacuum

We demonstrate all-optical sympathetic cooling of a laser-trapped microsphere to sub-Kelvin temperatures, mediated by optical binding to a feedback-cooled adjacent particle. Our study opens prospects for multi-particle quantum entanglement and sensing in levitated optomechanics. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License.