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

We study theoretically how excitations due to spontaneous emission and trap fluctuations combine with elastic collisions to change the momentum distribution of a trapped nondegenerate one-dimensional (1D) Bose gas. Using calculated collisional relaxation rates, we first present a semianalytical 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 1D Bose gases evolve due to heating processes in the absence of diffractive collisions that might thermalize the gases.