Vortex Lattice Formation in Spin–Orbit-Coupled Spin-2 Bose–Einstein Condensate Under Rotation

Abstract

Abstract: We investigate the vortex lattice configuration in a rotating spin orbit-coupled spin-2 Bose–Einstein condensate confined in a quasi-two-dimensional harmonic trap. By considering the interplay between rotation frequency, spin–orbit couplings, and interatomic interactions, we explore a variety of vortex lattice structures emerging as a ground state solution. Our study focuses on the combined effects of spin–orbit coupling and rotation, analyzed by using the variational method for the single-particle Hamiltonian. We observe that the interplay between rotation and Rashba spin–orbit coupling gives rise to different effective potentials for the bosons. Specifically, at higher rotation frequencies, isotropic spin–orbit coupling leads to an effective toroidal potential, while fully anisotropic spin–orbit coupling results in a symmetric double-well potential. To obtain these findings, we solve the five coupled Gross–Pitaevskii equations for the spin-2 BEC with spin–orbit coupling under rotation. Notably, we find that the antiferromagnetic, cyclic, and ferromagnetic phases exhibit similar behavior at higher rotation.