Layer-selective chirality switch in bilayer graphene intercalated by Janus monolayers

We predict that intercalating bilayer graphene with nonmagnetic WSSe or magnetic MnSSe Janus monolayers induces a layer-selective switch of the in-plane Rashba spin texture, resulting in opposite spin current directions in the top and bottom graphene layers. First-principles calculations reveal that both Janus monolayers decouple the two graphene layers while simultaneously inducing opposite signs of the proximity-induced Rashba spin-orbit coupling in each. Tight-binding modeling of the proximitized layers, combined with Rashba-Edelstein charge-to-spin conversion calculations, confirms that the spin current direction can be independently controlled by gating the top or bottom graphene layer. Bilayer graphene intercalated by Janus monolayers thus represents a promising platform for gate-tunable, layer-selective spintronic devices.