Modulation of orbital torque on nanoparticles by spin angular momentum via inter-particle light-induced force

摘要

In the optical manipulation, although the spin angular momentum (SAM) makes trapped objects spinning, the orbital angular momentum (OAM) of Laguerre-Gaussian (LG) beam enables to lead the spinning and orbital motion. However, we theoretically discovered that the SAM could modulate the OAM-induced orbital motion of multiple nanoparticles (NPs); the orbital torque exerted on NPs under the LG beam was modulated by the SAM via the inter-particle light-induced force. Our discovery explore a new physical aspect of many-body dynamics of NPs based on the SAM-OAM coupling.