They show that stochastic classical field simulations using Gross-Pitaevskii equations in three spatial dimensions reproduce the main experimental findings of Pigneur et al. [Phys. Rev. Lett. 120, 173601 (2018)]. They give an analytic solution describing the short time evolution through multimode dephasing. For longer times, the observed relaxation to a phase-locked state is caused by nonlinear dynamics beyond the sine-Gordon model, induced by the longitudinal confinement potential and persisting even at zero temperature. Finally, they analyze different experimentally relevant trapping geometries to mitigate these effects. Their results provide the basis for future experimental implementations aiming to study nonlinear and quantum effects of the relaxation in extended bosonic Josephson junctions.

For more information see:

Relaxation in an extended bosonic Josephson junction, J.-F. Mennemann, I. E. Mazets, M. Pigneur, H. P. Stimming, N. J. Mauser, J. Schmiedmayer, and S. Erne, Phys. Rev. Research 3, 023197 – Published 10 June 2021