  Tuning the near-field using all-dielectric nano-antennae offers a promising
approach for trapping atoms, which could enable strong single-atom/photon
coupling. Here we report the simulation results of an optical trapping concept,
in which a silicon nano-antenna produces a trapping potential for atoms in a
chip-scale configuration. Using counter-propagating incident fields,
bichromatically detuned from the atomic cesium D-lines, we numerically
investigate the dependence of the optical potential on the nano-antenna
geometry. We tailor the near-field potential landscape by tuning the evanescent
field of the waveguide using a toroidal nano-antenna, a configuration that
enables trapping of ultracold Cs atoms.
