Vortical Solitons of Three-Dimensional Bose-Einstein Condensates under Both a Bichromatic Optical Lattice and Anharmonic Potentials

We study Bose–Einstein condensate vortical solitons under both a bichromatic optical lattice and anharmonic potential.The vortical solitons are built in the form of a layer-chain structure made up of two fundamental vortices along the bichromatic optical lattice direction,which have not been reported before in the three-dimensional Bose–Einstein condensate.A variation approach is applied to find the optimum initial solutions of vortical solitons.The stabilities of the vortical solitons are confirmed by the numerical simulation of the time-dependent Gross–Pitaevskii equation.In particular,stable Bose–Einstein condensate vortical solitons with fundamental vortices of different atomic numbers in the external potential within a range of experimentally achievable timescales are found.We further manipulate the vortical solitons to an arbitrary position by steadily moving the bichromatic optical lattice,and find a stable region for the successful manipulation of vortical solitons without collapse.These results provide insight into controlling and manipulating the Bose–Einstein condensate vortical solitons for macroscopic quantum applications.