Nonreciprocal transverse optical binding forces in dielectric-metal heterodimers
Phys. Rev. B 112, 085101 – Published 4 August, 2025
DOI: https://doi.org/10.1103/7wn7-kq98
Abstract
Reciprocal optical binding forces between identical particles enable micron- and nanosized multiparticles to form a variety of stable static configurations. In general, the equilibrium interparticle distances are fixed and difficult to regulate. However, we demonstrate analytically that these distances can be continuously varied and even abruptly altered in dielectric-metal heterodimers driven by nonreciprocal transverse optical binding forces. These distances are crucial for determining the stable center of mass and configuration of the heterodimer. Specifically, the stability and equilibrium distances depend on the particle size and incident wavelength and can be tuned through the interplay between electric dipolar, magnetic dipolar, and electric-magnetic dipolar coupling components of the optical binding force. Moreover, the nonreciprocal nature of the binding force drives diverse nonequilibrium translations of the entire dimer as well as the attraction and repulsion of two particles. Importantly, the equilibrium distances, overall stability, and dynamics of the heterodimer can be modulated by the polarized angle of incident light. The results provide perspectives for the dynamical optical manipulation of multiparticle systems, shape-changing nanorobots, and phase-change arrays.
