Lateral shifting of gold particles on a metal surface

Abstract Owing to the intricate interplay between light and matter, the scattering optical force has garnered considerable attention in scientific research. This force invariably propels particles along the trajectory of light propagation. Intriguingly, the spin–orbit coupling effect of light has been observed to elicit a lateral optical force on metal nanoparticles, a phenomenon that defies conventional intuition, stemming from the rotation of electric field components. In this study, we present a demonstration of an augmented lateral force acting upon a particle when illuminated by a vector beam. To gain a deeper understanding of the lateral shifting effect, we have meticulously analyzed the influences of various factors, including the incident angle, particle size, spin states, and gap sizes. Our findings hold promise for advancing developments in particle sorting, contributing to the refinement and enhancement of related technologies.