Interlayer Exchange Coupling Mediated by a Bulk Rashba Semiconductor

Spin orbit coupling (SOC) in solids is a crucial ingredient in spintronic and magnetoelectronic phenomena. An example of SOC in solids is the 3D Rashba effect that arises in materials with broken inversion symmetry such as BiTeX (X=I,Cl and Br). These bismuth tellurohalides exhibit a giant Rashba coupling and are known as bulk Rashba semiconductors. In this talk, we present a RKKY theory for the interlayer exchange coupling in ferromagnet-BiTeX-ferromagnet trilayers. Due to the helical in-plane spin textures and associated Berry phase of the low-energy electrons, the interlayer exchange coupling as a function of layer thickness is found to exhibit unconventional dependence on the Rashba SOC.