Studying fundamental physics using a levitated optomechanical system*

Measuring tiny forces and momentum transfers can enable many tests of fundamental physics. Levitated optomechanical systems in high vacuum have shown outstanding force and momentum sensitivity due to their extremely low thermal noise, coupled with the ability to precisely control their electric charge state. While further improvements such as scaling up the sensors to large arrays are underway, applications have already been made to search for composite dark matter and millicharged particles. By further controlling the spin degree of freedom of a 10pg mass microsphere, the force and momentum sensitivity have been improved to <1aN/sqrt(Hz) and <100MeV/c respectively, therefore enabling levitated microspheres to be a powerful tool in detecting weakly interacting particles and recoils from single radioactive decays. Extending this scheme to nanospheres shows the potential to search for sterile neutrinos from kinematic reconstruction.