Equilibrium and scattering properties of a nonlocal three-soliton molecule in Bose–Einstein condensates with competing nonlinearities

Abstract

We carry out numerical and variational investigation of equilibrium and scattering properties of a bright three-soliton molecule in Bose–Einstein condensates with competing local and nonlocal nonlinearities in one-dimensional geometry. Our model predicts that the degree of the nonlocality and the soliton phase may strongly affect the binding energy and the soliton width. We show that the interaction of three solitons depends on their separation distance and on their relative phase. The scattering properties of these composite nonlinear structures by Gaussian potential barrier are analyzed variationally and numerically. It is found that stable transmission and reflection where the molecular structure is preserved can occur only for a specific barrier height and soliton velocity.