Dipolar Matter-Wave Soliton in One-Dimensional Optical Lattice with Tunable Local and Nonlocal Nonlinearities

Abstract

We study dipolar Bose–Einstein condensate (BEC) solitons in a one-dimensional optical lattice with the combined effect of local and nonlocal nonlinearities. The local nonlinearity is imposed by a magnetic or optical field via the Feshbach (FB) resonance. In contrast, the nonlocal nonlinearity is created by the long-range dipole–dipole interaction among the condensates. The orientations of the dipoles are directed by a rotatable uniform external field, which gives rise to a controllable nonlocal nonlinearity resulting from the angle θ between the direction of the dipole and the elongation of the lattice. If the lattice is sufficiently deep, this model can be described by the Gross–Pitaevskii equation (GPE) with tunable local and nonlocal nonlinear strengths (\(g\) and θ respectively). The formation, motion, and collision of the solitons in this system are studied by numerical simulations. The combined effect of the local and nonlocal nonlinearities gives a controllable scheme for all these characteristics via the relation between \(g\) and θ.