Unpredictable condensate–depletion dynamics in one-dimensional power-law traps

Abstract

The dynamic depletion of a trapped one-dimensional Bose–Einstein condensate (BEC) that is driven by laser stirring is numerically explored using beyond mean-field methods. For this purpose, the multi-configurational time-dependent Hartree method for bosons (Alon et al 2008 Phys. Rev. A 77 033613) is applied. In order to induce the depletion, the BEC is excited by a negative Gaussian potential (dimple) whose depth is modulated with time. The BEC is examined in various trapping geometries, with different interactions, and the condensate depletion is recorded as a function of time. A general power–law trap is considered that can be experimentally generated and shaped by the holographic methods of Bruce et al (2011 Phys. Rev. A 84 053410). The chief goal is to explore the interplay between trapping geometry and interactions in defining the depletion dynamics. It is chiefly found, that the details of these depletion dynamics are unpredictable and determined by a combination of the principle dimple depth, trap, and interactions. One significant feature of this work is that quite a number of plateaus is reached in the aforementioned dynamics.