A background-free optically levitated charge sensor

Understand

Optically levitated macroscopic objects are a powerful tool in the field of force sensing, owing to high sensitivity, absolute force calibration, environmental isolation and the advanced degree of control over their dynamics that have been achieved.

• However, limitations arise from the spurious forces caused by electrical polarization effects that, even for nominally neutral objects, affect the force sensing because of the interaction of dipole moments with gradients of external electric fields.
• In this paper we introduce a new technique to model and eliminate dipole moment interactions limiting the performance of sensors employing levitated objects.
• This process leads to the first noise-limited measurement with a sensitivity of $3.3\times10^{-5}e$.