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arXiv · 2402.19245

Feedback cooling a levitated nanoparticle's libration to below 100 phonons

Jialiang Gao·Fons van der Laan·Joanna A. Zielinska·Andrei Militaru·Lukas Novotny·Martin Frimmer
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Abstract

Macroscopic rotors are interesting model systems to test quantum theory and for quantum sensing. A promising approach for bringing these systems to the quantum regime is to combine sensitive detection with feedback cooling to reduce the thermal occupation of the mechanics. Here, we implement a backward-scattering scheme to efficiently detect all three libration modes of an optically levitated nanoparticle. We demonstrate parametric feedback cooling of all three libration degrees of freedom to below 16~mK, with one of the modes reaching the temperature of 1.3~mK, corresponding to a mean phonon number of 84. Finally, we characterize the backward-scattering scheme by determining its measurement efficiency to be 0.5\%.

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Jialiang Gao, Fons van der Laan, Joanna A. Zielinska, Andrei Militaru, Lukas Novotny, Martin Frimmer. 2024-02-29. Feedback cooling a levitated nanoparticle's libration to below 100 phonons. https://arxiv.org/abs/2402.19245

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