Giant Rashba spin-orbit coupling on light-element polar superlattices

We present a new strategy to amplify the spin-orbit coupling (SOC) effect in a simple metal-based polar superlattices with light elements to create a giant Rashba SOC up to αR≈3.80 eV {} with negative sign. First-principles calculations demonstrate that the giant αR originates from optimizing the internal electric field, which comes from the polarity, charge transfer, and superlattice systems. This strategy provides an effective way to design a next-generation spintronics device without the use of heavy elements.