Dipolar matter-wave solitons in two-dimensional anisotropic discrete lattices

TL;DR

This paper demonstrates the existence and dynamics of 2D dipolar matter-wave solitons in anisotropic optical lattices, revealing their mobility, collision behaviors, and stability under various anisotropic conditions.

Contribution

It introduces the concept of isotropy-pattern solitons in anisotropic dipolar BECs and explores their motion, collisions, and stability in a novel 2D anisotropic lattice setting.

Findings

Existence of freely moving isotropy-pattern solitons in anisotropic lattices

Identification of four collision types between solitons

Stability of solitons under magnetic field rotation

Abstract

We numerically demonstrate two-dimensional (2D) matter-wave solitons in the disk-shaped dipolar Bose-Einstein condensates (BECs) trapped in strongly anisotropic optical lattices (OLs) in a disk's plane. The considered OLs are square lattices which can be formed by interfering two pairs of plane waves with different intensities. The hopping rates of the condensates between two adjacent lattices in the orthogonal directions are different, which gives rise to a linearly anisotropic system. We find that when the polarized orientation of the dipoles is parallel to disk's plane with the same direction, the combined effects of the linearly anisotropy and the nonlocal nonlinear anisotropy strongly influence the formations, as well as the dynamics of the lattice solitons. Particularly, the isotropy-pattern solitons (IPSs) are found when these combined effects reach a balance. Motion, collision and rotation of the IPSs are also studied in detail by means of systematic simulations. We further find that these IPSs can move freely in the 2D anisotropic discrete system, hence giving rise to an anisotropic effective mass. Four types of collisions between the IPSs are identified. By rotating an external magnetic field up to a critical angular velocity, the IPSs can still remain localized and play as a breather. Finally, the influences from the combined effects between the linear and the nonlocal nonlinear anisotropy with consideration of the contact/local nonlinearity are discussed too.