2021/06/30 by Christopher D. Mink, Axel Pelster, Jens Benary +2
Physics and Astronomy · #physics.atom-ph #cond-mat.quant-gas
paper · pdf · doi:10.21468/scipostphys.12.2.051
published as SciPost Phys. 12, 051 (2022) · 22 pages, 6 figures
arxiv created 2021/11/26 · arxiv updated 2022/02/02
The truncated Wigner approximation is an established approach that describes the dynamics of weakly interacting Bose gases beyond the mean-field level. Although it allows a quantum field to be expressed by a stochastic c-number field, the simulation of the time evolution is still very demanding for most applications. Here, we develop a numerically inexpensive approximation by decomposing the c-number field into a variational ansatz function and a residual field. The dynamics of the ansatz function is described by a tractable set of coupled ordinary stochastic differential equations for the respective variational parameters. We investigate the non-equilibrium dynamics of a three-dimensional Bose gas in a one-dimensional optical lattice with a transverse isotropic harmonic confinement and neglect the influence of the residual field. The accuracy and computational inexpensiveness of our method are demonstrated by comparing its predictions to experimental data.