Self-bending of spatial solitons in nonlinear interface governed by drift and diffusion

We study numerically and theoretically the behaviour of bright spatial soliton in one-dimensional interface formed by drift and diffusion nonlinearity, in one-medium, and linear the other medium. It is known that the diffusion mechanism gives rise to self bending effect, but when the soliton is launched to nonlinear interface, very interesting phenomena is observed. The soliton is reflected by nonlinear interface but due to drift nonlinearity, is self-bending to nonlinear interface. This process is repeated many times along the propagation distance, in consequence surfaces waves is formed. We also show that the trajectory of the soliton is parabolic with particle method.