title: Lateral optical force on chiral particles near a surface.
abstract: Light can exert radiation pressure on any object it encounters and that resulting optical force can be used to manipulate particles. It is commonly assumed that light should move a particle forward and indeed an incident plane wave with a photon momentum ħk can only push any particle, independent of its properties, in the direction of k. Here we demonstrate, using full-wave simulations, that an anomalous lateral force can be induced in a direction perpendicular to that of the incident photon momentum if a chiral particle is placed above a substrate that does not break any left-right symmetry. Analytical theory shows that the lateral force emerges from the coupling between structural chirality (the handedness of the chiral particle) and the light reflected from the substrate surface. Such coupling induces a sideway force that pushes chiral particles with opposite handedness in opposite directions.
authors.affiliation: Department of Physics and Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: S B
authors.initials: SB
authors.lastname: Wang
authors.affiliation: Department of Physics and Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: C T
authors.initials: CT
authors.lastname: Chan
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006046:Gold / Q000737:chemistry / Q000528:radiation effects; D008027:Light; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry / Q000528:radiation effects*; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry / Q000528:radiation effects*; D017785:Photons; D012542:Scattering, Radiation; D013499:Surface Properties / Q000528:radiation effects; D013816:Thermodynamics
chemical_list: D052638:Particulate Matter; D006046:Gold