Spin-orbit correlations and exchange-bias control in twisted Janus dichalcogenide multilayers

Abstract: Janus dichalcogenide multilayers provide a paradigmatic platform to engineer electronic phenomena dominated by spin-orbit coupling. Their unique spin-orbit effects stem from local mirror symmetry breaking in each layer, which induces a colossal Rashba spin-orbit effect in comparison with the conventional dichalcogenide counterparts. Here we put forward twisted dichalcogenide bilayers as a simple platform to realize spin-orbit correlated states. We demonstrate the emergence of flat bands featuring strong spin-momentum locking and the emergence of non-collinear symmetry broken states when interactions are included. We further show that the symmetry broken states can be controlled by means of a magnetic substrate, strongly impacting the non-collinear magnetic texture of the moire unit cell. Our results put forward twisted Janus multilayers as a powerful platform to explore spin-orbit correlated physics, and highlighting the versatility of magnetic substrates to control unconventional moire magnetism.