Oscillations and interactions of dark and dark–bright solitons in Bose–Einstein condensates

Abstract

Solitons are among the most distinguishing fundamental excitations in a wide range of nonlinear systems such as water in narrow channels, high-speed optical communication, molecular biology and astrophysics. Stabilized by a balance between spreading and focusing, solitons are wave packets that share some exceptional generic features such as form stability and particle-like properties. Ultracold quantum gases represent very pure and well-controlled nonlinear systems, therefore offering unique possibilities to study soliton dynamics. Here, we report on the observation of long-lived dark and dark–bright solitons with lifetimes of up to several seconds as well as their dynamics in highly stable optically trapped 87Rb Bose–Einstein condensates. In particular, our detailed studies of dark and dark–bright soliton oscillations reveal the particle-like nature of these collective excitations for the first time. In addition, we discuss the collision between these two types of solitary excitation in Bose–Einstein condensates. Solitons are encountered in a wide range of nonlinear systems, from water channels to optical fibres. They have also been observed in Bose–Einstein condensates, but only now have such ‘ultracold solitons’ been made to live long enough for their dynamical properties to be studied in detail.

Cite this article

Becker, C., Stellmer, S., Soltan-Panahi, P. et al. Oscillations and interactions of dark and dark–bright solitons in Bose–Einstein condensates. Nature Phys 4, 496–501 (2008). https://doi.org/10.1038/nphys962

View full text

>> Full Text:   Oscillations and interactions of dark and dark–bright solitons in Bose–Einstein condensates