Direct Observation of Sub-Poissonian Number Statistics in a Degenerate Bose Gas.

We report the direct observation of Sub-Poissonian number fluctuations for a degenerate Bose gas in an optical trap [1]. Reduction of number fluctuations below the Poissonian limit is observed for average numbers that range from 300 to 12 atoms by a controlled reduction of the confining potential in one dimension. The optical trap composed of five optical sheets is integrated with single atom detection with nearly unit quantum efficiency, enabling a direct and in-situ measurement of atom statistics [2]. Future work includes the generation of arbitrary many-body number states, the study of many-body quantum tunneling, and a statistical study of quantum critical phenomena. [1] C.-S. Chuu, F. Schreck, T. P. Meyrath, J. L. Hanssen, G. N. Price, and M. G. Raizen, ``Direct Observation of Sub-Poissonian Number Statistics in a Degenerate Bose Gas,'' Phys. Rev. Lett. 95, 260403 (2005). [2] T. P. Meyrath, F. Schreck, J. L. Hanssen, C.-S. Chuu, and M. G. Raizen, ``Bose-Einstein Condensate in a Box,'' Phys. Rev. A 71, 041604 (2005).