JILA Science Seminar - Yu-Han Tseng

Speaker: Yu-Han Tseng

Title: Measuring fundamental particle interactions with levitated optomechanical sensors

Abstract: The development of levitated optomechanics has opened unique opportunities for studying weakly coupled fundamental particles that are beyond the reach of conventional detectors. This talk will describe a new type of force sensor based on optically trapped, femtogram-scale nanoparticles. In ultra-high vacuum, where thermal noise is mitigated, the sensitivity of these sensors is primarily limited by quantum measurement noise, enabling the measurement of impulsive forces near the standard quantum limit. As a proof of principle, I will discuss a recent experiment where these sensors are applied to measure the momentum imparted by collisions of individual gas particles. I will further describe a search for scattering events of particle dark matter, where for certain models this initial search outperforms the sensitivity of large underground detectors. In the near future, extensions of the techniques developed here could enable measurement of the momentum of individual neutrinos.