Optomechanical Kerker effect

TL;DR

This paper predicts a novel optomechanical Kerker effect where vibrating nanoparticles exhibit strong, tunable directional scattering without magnetic resonances, revealing new multipolar light-matter interactions.

Contribution

It introduces the concept of an optomechanical Kerker effect driven by particle vibrations, enabling tunable directionality and polarization-dependent scattering without magnetic resonances.

Findings

Achieves directional scattering with directivity up to 5.25

Demonstrates inelastic polarization-dependent scattering

Reveals multipolar interactions between light and mechanical motion

Abstract

Tunable directional scattering is of paramount importance for operation of antennas, routing of light, and design of topologically protected optical states. For visible light scattered on a nanoparticle the directionality could be provided by the Kerker effect, exploiting the interference of electric and magnetic dipole emission patterns. However, magnetic optical resonances in small sub-100-nm particles are relativistically weak. Here, we predict inelastic scattering with the unexpectedly strong tunable directivity up to 5.25 driven by a trembling of small particle without any magnetic resonance. The proposed optomechanical Kerker effect originates from the vibration-induced multipole conversion. We also put forward an optomechanical spin Hall effect, the inelastic polarization-dependent directional scattering. Our results uncover an intrinsically multipolar nature of the interaction between light and mechanical motion. They apply to a variety of systems from cold atoms to two-dimensional materials to superconducting qubits and can be instructive to engineer chiral optomechanical coupling.