Dynamics of ring solitons in an expanding cloud of a Bose-Einstein condensate

Ju-Kui Xue

Suying Zhang, Guoquan Yang, Siyu Xie +1 more

Guoquan Yang, Siyu Xie, Yan Jie Zhao +2 more

Lin-Xue Wang, Hui Liu, Hongli Yang +5 more

A. M. Kamchatnov, Bulat Irekovich Suleimanov, E. N. Tsoy

In this paper, we derive equations for the dynamics of ring dark solitons in an expanding cloud of a two-dimensional Bose-Einstein condensate. Assuming that the soliton's width is much smaller than its radius, we obtain the Hamilton equations for its evolution. Then they are transformed into the Newton equation, which is more convenient for applications. The general theory is illustrated by the solution of the Newton equation for the case of the axially symmetric condensate cloud, which expands after switching off a harmonic trap. The validity of our approximate analytical approach is confirmed by comparison with the results of numerical simulations of the Gross-Pitaevskii equation.

Stephen Eckel, A. Kumar, Ted Jacobson A +2 more

We study the dynamics of a supersonically expanding ring-shaped Bose-Einstein condensate both experimentally and theoretically. The expansion redshifts long-wavelength excitations, as in an expanding universe. After expansion, energy in the radial mode leads to the production of bulk topological excitations - solitons and vortices - driving the production of a large number of azimuthal phonons and, at late times, causing stochastic persistent currents. These complex nonlinear dynamics, fueled by the energy stored coherently in one mode, are reminiscent of a type of "preheating" that may have taken place at the end of inflation.