Dynamical excitation of spin-orbit coupled spin-1 Bose-Einstein condensate in a narrow box trap

We demonstrate the dynamics of a spin-1 ferromagnetic Bose-Einstein condensate (BEC) with Rashba spin-orbit (SO) coupling in a narrow square box trap when an obstacle potential is moving in it. The ground-state energy would be enhanced with the box trap becomes narrower. From the Bogoliubov analytical excitation spectrum lines, we obtain the dependence of critical excitation velocity and momentum on the trap geometry under different SO coupling. Numerically, when the obstacle moves along the direction of plane wave ground state, in addition to spin-density waves being excited periodically, a long density belt accompanied by density island chain is found ahead of the obstacle. Such density distribution is mainly determined by the narrow box trap. A series of density islands arranged more closely are generated as the obstacle moves along opposite direction. There exists another velocity threshold for different density excitation under a larger SO coupling.