Levitodynamic sensors for fundamental and applied physics

Optically levitated nanoparticles cooled to the ground state of a confining optical potential represent a new quantum system that has applications in both fundamental and applied physics. In this talk I will describe our work that has developed methods for simultaneously cooling the rotational and translation modes of non-spherical particles using coherent scattering within a high finesse optical cavity.  I will then outline a new non-intrusive characterization method for nanoparticles, based on the measurement of their rotational and oscillatory motion when optically levitated at low pressure. Here, morphology and size differences as small as a few nanometers can be resolved using this technique offering a new optical spectroscopic tool for non-contact characterization of single nanoparticles in the absence of a substrate. Lastly, I will describe more recent work that is developing a directional force sensor to test composite dark matter models using levitated nanoparticles in vacuum.