Magnetic Chiral Light

We present a result derived from the optical chirality continuity equation that shows the existence of a source term describing optical chirality generation through the interactions of the magnetic induction field with a source current, without contributions from the electric field. This framework is validated through a metasurface-based methodology. Using a lossless, all-dielectric nanoparticle array, we engineer an in-plane rotating electric field that generates out-of-plane optical magnetism. This array exhibits a far-field circular dichroism of 0.47 and a high-quality factor on the order of 10^6. The presented findings demonstrate the feasibility of inducing chiral optical responses from a magnetic source. This work establishes a new paradigm for structured photonic media, offering insights into the design of nanophotonic devices that exploit optical magnetism for chiral light-matter interactions.