  Plasmonic vortices (PV) excited by a highly focused radially polarized
optical vortex (RPOV) beam on a metal surface are investigated experimentally
and theoretically. The proposed method reveals a direct phase singularity and
orbital angular momentum (OAM) transfer from an incident structured beam to its
counterpart in surface plasmon with dynamic, reconfigurable and high-efficiency
advantages. The plasmonic field pattern, phase distributions, Poynting vector
and focusing efficiency of PV are studied in detail. Experimental verification
further shows that nanoparticles can be confined and manipulated within the
region of PV and orbital rotation speed of the trapped particles is altered
dynamically by changing the topological charge of the incident light.
