Plasmonic lateral forces on chiral spheres

Abstract

We show that the optical force exerted on a finite size chiral sphere by a surface plasmon mode has a component along a direction perpendicular to the plasmon linear momentum. We reveal how this chiral lateral force, pointing in opposite directions for opposite enantiomers, stems from an angular-to-linear crossed momentum transfer involving the plasmon transverse spin angular momentum density and mediated by the chirality of the sphere. Our multipolar approach allows us discussing the inclusion of the recoil term in the force on a small sphere taken in the dipolar limit and observing sign inversions of the lateral chiral force when the size of the sphere increases.

8 pages, 5 figures

References in corpus (5)

• Backward Pulling Force from a Forward Propagating Beam
• Measuring the Transverse Spin Density of Light
• Transverse spin and momentum in two-wave interference
• The optical torque on small bi-isotropic particles
• Chiral near fields generated from plasmonic lattices

Cited by in corpus (8)

• Macroscopic direct observation of optical spin-dependent lateral forces and left-handed torques
• Unified theory to describe and engineer conservation laws in light-matter interactions
• Emergence of transverse spin in optical modes of semiconductor nanowires
• Probing the optical chiral response of single nanoparticles with optical tweezers
• Dominant chiral optical forces in vicinity of optical nanofibers
• Dynamical characteristics of electromagnetic field under conditions of total reflection
• Transverse spin angular momentum of space-time surface plasmon polariton wave packet
• Optical force and torque on small particles induced by polarization singularities