Benjamin Siegel

Levitated microspheres have proven to be extremely sensitive force and momentum detectors, enabling searches for physics beyond the Standard Model. By monitoring the position and charge of such spheres, our lab has already set limits on relic millicharged particles, searched for composite dark matter and detected nuclear decays through mechanical recoils. We plan to improve the sensitivity of these rare event experiments by scaling to an array of traps. Using a time division multiplexing approach for creating the array enables independent control over each trap. We have successfully demonstrated trapping and reorganization of up to 49 spheres, with their motion monitored via a high speed camera. Furthermore, we have realized a scalable real-time feedback protocol that is currently limited by the bandwidth of our photodiodes and acousto-optic deflectors. This protocol utilizes back focal plane imaging and backscattered light detection and will be able to independently cool the center-of-mass motion of each sphere. In the future, this setup will increase our cross section for dark matter scattering events, with the added benefit of improving noise rejection via correlated motion of the array.