Quantum coherence establishment of Bose–Einstein condensates induced by random system dissipation

By using a weak imaginary random potential to simulate the random system dissipation and considering the quantum many-body effect, the role of random system dissipation in the quantum coherence establishment of Bose-Einstein condensates (BECs) is studied. It is found that even very weak random system dissipation may induce an obvious interference pattern between two initially independent BECs after the overlapping. Moreover, the random system dissipation has no effect on the spatial period of the interference fringes, which is identical to that observed in the current interference experiments. Under the assumption of weak dissipation, increasing the dissipation strength may accelerate the construction of the observable relative phase. Other behaviours of the interference are also investigated. The theoretical analysis and the numerical simulation show good consistency. This sort of interference has an observable effect, which significantly differs from other quantum interference mechanisms. The work may provide further theoretical basis for the future interference experiment of molecular BECs (Kohstall et al 2011 New J. Phys. 13 065027), considering the possible dissipation of the molecular BECs (e. g. the destruction of the weakly bound Feshbach molecules and the dissipation of the condensate fraction).