Effective gyration of polar vortex arrays controlled by high orbital angular momentum of light

The electric field of an optical vortex (OV) beam displays a specific winding pattern determined by its spatial variation and angular momentum. An OV beam can serve as a optical spanner, which exerts a force torque to rotate particles around the beam axis. In this work, using first-principles-based calculations, we demonstrate that an OV beam with high orbital angular momentum (OAM) can induce local electric dipoles to self-order and form a vortex array distributed along azimuthal directions. More importantly, owing to its intrinsic symmetry, the evolution of the vortex array with time can be viewed as an effective spinning around the central axis, while its rotation speed is also connected to the OAM value. Our study thus presents an alternative approach for manipulating polar vortices using the optical field apart from mechanical and electric stimuli, and especially for a deterministic control of vortex dynamics that is critical in the application of memory devices.