Tunable and enhanced Rashba spin-orbit coupling in iridate-manganite heterostructures

Tailoring spin-orbit interactions and Coulomb repulsion are the key features to observe exotic physical phenomena such as magnetic anisotropy and topological spin texture at oxide interfaces. Our study proposes a platform for engineering magnetism and spin-orbit coupling at the LaMnO3/SrIrO3 (3d-5d) oxide interface by tuning the LaMnO3 growth conditions, which controls the lattice displacement and spin-correlated interfacial coupling through charge transfer. We report a tunable and enhanced interface-induced Rashba spin-orbit coupling where the spin relaxation mechanism varies with magnetic behavior of the underlying LaMnO3 layer. The x-ray spectroscopy measurements reveal the quantitative valence states of Mn and their impact on charge transfer. Our angle-dependent magnetoresistance measurements also reflects the signature of magnetic proximity effect in SrIrO3 and can be tuned with the magnetic nature of LaMnO3 in a LaMnO3/SrIrO3 bilayer. Our work demonstrates a route to engineer the interface-induced Rashba spin-orbit coupling and magnetic proximity effect at the 3d-5d oxide interface for spintronics applications.