Controlling electric dipole moments in levitated optomechanics

Abstract

Highly sensitive levitated optomechanical systems can be used as precise acceleration and force sensors to search for fundamental physics. Eliminating the net charge on these systems reduces the most significant coupling to external electric fields yet leaves the issue of backgrounds created by higher order multipole moments in the charge distribution of the levitated sensors. In many high sensitivity applications of levitated optomechanical sensors, dipole induced forces can be many orders of magnitude larger than the forces of interest. Thus, techniques to measure, control, and ultimately eliminate dipole generated backgrounds may be required to realize numerous experiments such as the search for millicharged particles, the exploration of new parameter space of dark matter mass with an array of levitated microspheres and possibly future work towards detection of gravitational entanglement between micron sized masses. This talk will discuss the application of controlled precessive torques to the electric dipole moment of a levitated microsphere in vacuum to reduce dipole-induced backgrounds by 2 orders of magnitude as well as work towards integrating such sensors in large arrays.