Photo-induced Non-collinear Magnetic Exchange Interactions in Rashba Magnetic Multilayers

Photon-dressing of electrons in light-driven materials is key to dynamically control the magnetic exchange coupling. In magnetic multilayers composed of spin-degenerate electron gases enclosed by ferromagnetic layers, periodic driving via irradiation facilitates the control of the indirect magnetic exchange interaction. However, their photo-irradiation does not induce non-collinear exchange couplings that are originally absent at equilibrium. Rashba semiconductors, such as BiTeI, exhibit a giant spin-orbit coupling arising from the lack of crystal inversion symmetry. At equilibrium, a Rashba magnetic multilayer, i.e., BiTeI sandwiched between two ferromagnetic layers along its stacking direction has an interlayer magnetic exchange interaction that uniquely consists of collinear components. In this work, we consider a monochromatically irradiated Rashba magnetic multilayer. In the high-frequency limit, we show that in addition to photon-dressing effects of the electronic bands, irradiation also considerably modulates the spin textures of photon-dressed bands. We also present our results on the generation and control of non-collinear exchange interactions mediated by photon-dressed electrons in Rashba magnetic multilayers.