Nanofiber-Based Optical Trapping of Cold Neutral Atoms

We present experimental techniques and recently demonstrated results related to the optimization and characterization of our recently demonstrated nanofiber-based atom trap. The atoms are confined in an optical lattice that is created using a two-color evanescent field surrounding the optical nanofiber. For this purpose, the polarization state of the trapping light fields has to be properly adjusted. We demonstrate that this can be accomplished by analyzing the light scattered by the nanofiber. Furthermore, we show that loading the nanofiber trap from a magneto-optical trap leads to sub-Doppler temperatures of the trapped atomic ensemble and yields a sub-Poissonian distribution of the number of trapped atoms per trapping site.