Eur. Phys. J. B 58, 269-278 (2007)
https://doi.org/10.1140/epjb/e2007-00230-4

Slowly moving matter-wave gap soliton propagation in weak random optical lattices

¹ Surface Physics Laboratory (National Key Lab), Fudan University, Shanghai, 200433, P.R. China
² Institute of Microsystem and Information Technology, CAS, Shanghai, 200050, P.R. China
³ State Key Laboratory of Optoelectronic Materials and Technologies, Zhongshan University, Guangzhou, 510275, P.R. China

Corresponding author: ^a xyjiang@mail.sim.ac.cn

Received: 7 March 2007
Revised: 22 June 2007
Published online: 8 September 2007

Abstract

We systematically investigate slowly moving matter-wave gap soliton propagation in weak random optical lattices. With the weak randomness, an effective-particle theory is constructed to show that the motion of a gap soliton is similar to a particle moving in random potentials. Based on the effective-particle theory, the effects of the randomness on gap solitons are obtained and the trajectories of gap solitons are well predicted. Moreover, the general laws that describe the movement depending on the weak randomness are obtained. We find that with an increase of the random strength, the ensemble-average velocity reduces slowly and the reflection probability becomes larger. The theoretical results based on the effective-particle theory are confirmed by the numerical simulations based on the Gross-Pitaevskii equation.