Lateral optical force on an isotropic dimer induced by high-order multiple scattering under arbitrary polarization states.

Generating lateral optical force (LOF) on mirror-symmetric objects without complex structured light fields remains a significant challenge in optical manipulation. While recent studies have shown that linear polarization can break symmetry to induce LOF on isotropic dimers via first-order scattering, extending this phenomenon to arbitrary polarization states under simple plane-wave illumination faces fundamental symmetry constraints. In this work, we report a fundamental distinction in the origin of LOF acting on an isotropic dimer under different polarization states. By establishing a rigorous multiple-scattering model, we reveal that while linear polarization induces symmetry breaking at the first-order interaction, the LOF under circular polarization is strictly forbidden at first order by symmetry and emerges only through higher-order electromagnetic re-scattering, reaching quantitative convergence at the fourth order for the representative parameter set studied here. This finding challenges the conventional intuition based on single-scattering approximations. Furthermore, in the Mie regime, the force is likewise governed by polarization-tuned mirror-symmetry breaking of the scattered field. These results show that polarization can switch the governing dynamics between low-order and high-order scattering, providing a theoretical blueprint for all-optical sorting and bidirectional transport.