Van der Waals meta-crystal for valleytronics

Spin-valley selective materials form the foundation of valleytronics—the transfer of information using the spin-polarized photoluminescence of two non-equivalent but energy-degenerate bands. While 2D transition metal dichalcogenides are the leading spin-valley selective materials, they exhibit weak light-matter interactions and require cryogenic temperatures to preserve spin-valley selectivity. This project proposes a novel engineered spiral meta-crystal, based on nanopatterning an assembly of randomly oriented monolayers. This structure enhances photoluminescence through increased optical thickness, while the spiral geometry restores spin-valley dichroism at room temperature. These advancements not only enable room-temperature valleytronics but also provide a platform for exploring spin-orbit interactions at the nanoscale.