Optical trap and control of a nanoparticle in vacuum towards a mixture with ultracold atoms

We design and build a new experimental setup to demonstrate a mixture of a single nanoparticle and laser-cooled atoms. This system aims for investigating the low-energy scattering of ultracold atoms by a dielectric nanoparticle. The wave nature of the cold atoms manifests itself in both elastic and inelastic cross sections. In the new experimental system at Yokohama National University, we demonstrated optical trapping and cooling of a glass nanoparticle in vacuum. The ballistic Brownian motion of the nanoparticle in the harmonic potential was observed. We also demonstrated parametric cooling of the center of mass motion of the nanoparticle. We discuss the prospects for realization of a mixture of a single nanoparticle and laser-cooled atoms.