Magnetic and Electric Transverse Spin Supported by Bianisotropic Metamaterials

ABSTRACT Spin is a fundamental property of light, playing a crucial role in both classical and quantum optics. In free space, light spin aligns with its propagation. However, light can exhibit transverse spin, where the spin direction is perpendicular to its propagation, in scenarios such as laterally confined electromagnetic waves including evanescent waves, spatially structured propagating waves, and focused waves, or bulk media with bianisotropy. In this work, we demonstrate a bianisotropic metamaterial that can support bulk waves with both electric and magnetic T‐spins, and observe T‐spin‐dependent scattering. Furthermore, we identify an interface mode formed by evanescent waves with opposite magnetic T‐spin angular momenta. Our findings offer a promising avenue for spin photonics devices and optical information processing.