Formation and propagation of matter-wave soliton trains

Abstract

Attraction between the atoms of a Bose-Einstein condensate renders it unstable to collapse, although a condensate with a limited number of atoms can be stabilized by confinement in an atom trap. However, beyond this number the condensate collapses. Condensates constrained to one-dimensional motion with attractive interactions are predicted to form stable solitons, in which the attractive forces exactly compensate for wave-packet dispersion. Here we report the formation of bright solitons of (7)Li atoms in a quasi-one-dimensional optical trap, by magnetically tuning the interactions in a stable Bose-Einstein condensate from repulsive to attractive. The solitons are set in motion by offsetting the optical potential, and are observed to propagate in the potential for many oscillatory cycles without spreading. We observe a soliton train, containing many solitons; repulsive interactions between neighbouring solitons are inferred from their motion.

Two-dimensional modulational instability in photorefractive media

“…As far as optics is concerned, MI has been studied in media with various mechanisms of nonlinear response including cubic [1], quadratic [3], nonlocal [4,5] and inertial [6,7] types of nonlinearity. Importantly, MI is not restricted to nonlinear optics but has also been studied in many other nonlinear systems including fluids [8], plasmas [9] and matter waves [10].In the context of optical beam propagation in nonlinear materials MI has usually been considered in media with spatially isotropic nonlinear properties. Recently a great deal of theoretical and experimental efforts have been devoted to studies of nonlinear optical effects and soliton formation in photorefractive crystals [11,12,13].…”

“…As far as optics is concerned, MI has been studied in media with various mechanisms of nonlinear response including cubic [1], quadratic [3], nonlocal [4,5] and inertial [6,7] types of nonlinearity. Importantly, MI is not restricted to nonlinear optics but has also been studied in many other nonlinear systems including fluids [8], plasmas [9] and matter waves [10].…”

Stable and mobile two-dimensional dipolar ring-dark-in-bright Bose–Einstein condensate soliton

“…among others [1]. In physical three-dimensional (3D) world, 1D bright solitons were observed in BEC of 7 Li [2] and 85 Rb atoms [3].…”

Stability of trapless Bose–Einstein condensates with two- and three-body interactions

“…Weakly interacting BECs atoms have stimulated intensive interest in the field of atomic matter waves and nonlinear excitations such as dark [15,16] and bright solitons [17,18,19]. A numerical study of the time-dependent GP equation is of interest, as this can provide solutions to many stationary and time-evolution problems.…”