A. Reinhard

Effect of optical-lattice heating on the momentum distribution of a one-dimensional Bose gas

We theoretically study how excitations due to spontaneous emission and trap fluctuations combine with elastic collisions to change the momentum distribution of a trapped non-degenerate one-dimensional (1D) Bose gas. Using calculated collisional relaxation rates, we first present a semi-analytical model for the momentum distribution evolution to get insight into the main processes responsible for the system dynamics. We then present a Monte-Carlo simulation that includes features that cannot be handled analytically, and compare its results to experimental data. These calculations provide a baseline for how integrable 1D Bose gases evolve due to heating processes in the absence of diffractive collisions that might thermalize the gases.

Coherent population transfer of ground state atoms into Rydberg states

We demonstrate experimentally and theoretically an efficiency of /spl sime/70%for excitation from the /sup 85/Rb 5S ground state to the 44D Rydberg state, using the technique of stimulated Raman adiabatic passage (STIRAP).