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arXiv · 2506.19739

Multimode feedback cooling of the collective modes of a Bose-Einstein condensate

Ryan J. Thomas·Jordan A. McMahon·Zain Mehdi·Stuart S. Szigeti·Simon A. Haine·Samuel Legge·John D. Close·Joseph J. Hope
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Abstract

We experimentally demonstrate cavity-free feedback cooling of the three lowest-lying collective modes of a Bose-Einstein condensate in a prolate harmonic trap. Using shadowgraph imaging as an in situ probe of the atomic density, we measure the time-dependent centers of mass and widths of the condensate in two dimensions and use these measurements to damp oscillations in the two visible dipole modes and the low-frequency quadrupole mode. By inducing oscillations in the condensate, we show that we can efficiently damp the dipole modes to a final mean phonon occupancy per atom of $<1$.

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Ryan J. Thomas, Jordan A. McMahon, Zain Mehdi, Stuart S. Szigeti, Simon A. Haine, Samuel Legge, John D. Close, Joseph J. Hope. 2025-06-24. Multimode feedback cooling of the collective modes of a Bose-Einstein condensate. https://doi.org/10.1103/jzw6-dn5h

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