Light-matter interactions in 3D chiral plasmonic nanostructures with geometric spin-orbit hybridization

<p dir="ltr">Chirality, either induced by geometry or motion, plays a pivotal role in optics and photonics. The interaction of light and matter lacking mirror symmetry induces intriguing optical phenomena such as circular dichroism (CD) and enhanced optical chirality density, inspiring various applications ranging from polarization control, optical sensing, and enantioselective detection to chiral light emission management and photocatalysis. Inspired by the spin and orbital angular momentum of light, we present a systematic framework that classifies and integrates chiral nanostructures formed through the spin and orbital motion of two-dimensional (2D) geometries with mirror symmetry. By systematically analyzing geometric asymmetry and rotational speed, we control both far-field CD and near-field optical chirality density, uncovering distinct yet complementary chiral responses arising from spin-orbit geometry. Inspired by spin-orbit interactions in light, we introduce and implement a geometric spin-orbit hybridization framework to design chiral nanostructures, demonstrating the potential for practical applications, including polarization-sensitive photothermal detection and plasmonic nano-needles with uniform and strong chirality density. Our findings establish a versatile platform for engineering chiral nanostructures, shedding light on advanced applications in nanophotonics and chiral light-matter interactions.</p>