Ultra-sensitive momentum detection using levitated microspheres*

Searching for small momentum transfers to micron-scale sensors is a promising approach to search for dark matter and to enable spectroscopy of nuclear decays in small particles. Levitated sensors can minimize thermal noise and have been shown to reach acceleration sensitivity as low as ~100ng/sqrt(Hz). These sensors also allow the detection of small momentum impulses. Applications of these techniques will be described, including searches for asymmetric dark matter recoils from the optically trapped sensors, as well as the mechanical detection of single nuclear decays with a momentum threshold <50MeV/c.