Electrically driven chiral emission from plasmonic tunnel junctions

Chirality plays a crucial role in a broad range of processes, including light-matter interactions in physics, chemistry, and biology, while quantum tunneling provides a promising mechanism for light generation at the nanoscale. By integrating tunnel junctions with chiral plasmonic nanohelicoids, we achieved electrically induced nanoscale generation of chiral light at the single-particle level. The tunneling-driven resonant excitation of chiral dipolar modes of the nanohelicoids results in emission of a vortex light beam possessing both spin angular momentum with handedness selectivity of more than 0.8 and orbital angular momentum equal in magnitude and opposite in sign. Our electrically driven approach offers a means for engineering photon spin generation at the nanoscale, highlighting its potential for next-generation optical components in display applications, as well as quantum information processing and photochemistry.