We demonstrate that achiral electric-dipole scatterers can mimic an interaction of light with chiral matter by generating far-field circular polarization upon scattering, even though the optical chirality of the incident field as well as that of the scattered light is zero. On the one hand, the presented effect originates from the fact that electric-dipole scatterers respond selectively only to the incident electric field, which eventually results in depolarization of the transmitted beam and in generation of far-field circular polarization. On the other hand, although the incident beam does not possess any optical chirality, it lacks reflection symmetry and therefore it is geometrically chiral. To experimentally demonstrate this effect, we utilize a cylindrical vector beam with spiral polarization and a spherical gold nanoparticle positioned on the optical axis-the axis of rotational symmetry of the system. Our experiment and a simple theoretical model address the fundamentals of duality symmetry in optics and chiral light-matter interactions, accentuating their richness and ubiquity yet in highly symmetric configurations.
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