Dragging spin-orbit-coupled solitons by a moving optical lattice

TL;DR

This paper demonstrates that a moving optical lattice can significantly extend the stable velocity range of spin-orbit-coupled solitons in Bose-Einstein condensates, overcoming limitations caused by SOC-induced non-Galilean invariance.

Contribution

The study introduces a method using a moving optical lattice to stabilize and extend the velocity range of 2D solitons affected by spin-orbit coupling.

Findings

Moving optical lattices expand the stable velocity interval for solitons.

Quasi-1D optical lattices provide stronger stabilization than 2D lattices.

Analytical insights support the numerical stability domain results.

Abstract

It is known that the interplay of the spin-orbit-coupling (SOC) and mean-field self-attraction creates stable two-dimensional (2D) solitons (ground states) in spinor Bose-Einstein condensates. However, SOC destroys the system's Galilean invariance, therefore moving solitons exist only in a narrow interval of velocities, outside of which the solitons suffer delocalization. We demonstrate that the application of a relatively weak moving optical lattice (OL), with the 2D or quasi-1D structure, makes it possible to greatly expand the velocity interval for stable motion of the solitons. The stability domain in the system's parameter space is identified by means of numerical methods. In particular, the quasi-1D OL produces a stronger stabilizing effect than its full 2D counterpart. Some features of the domain are explained analytically.