Optical trapping and binding in skyrmionic beams

We explore optical trapping and binding in skyrmionic optical beams generated by combining pairs of focused Laguerre-Gaussian with different orders and orthogonal polarisations, using computer simulations. Typically, the resultant focal region of the skyrmionics beam is annular but with intensity and polarisation varying around the ring. Dielectric particles are trapped in the ring but orbit at a speed that varies with the intensity variation. Absorbing particles will additionally couple to the changing polarisation and may experience a spin-torque as they orbit. In this study we construct skirmionic beams in a computer model, and analyse the coupling of spin and orbital angular momentum to different types of particle. The binding and dynamics of multiple particles trapped in skyrmionics beams will also be examined.