Spin-to-charge conversion through Rashba coupling in SrTiO₃-based two-dimensional electron gases

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO₃ (LAO) and SrTiO₃ (STO) has attracted much attention from the oxide electronics community. Among its many low dimensional physical effects, the strong Rashba spin-orbit coupling present at the interface could be exploited for spin-to-charge interconversion, which presents advantages for the future of spintronics. We will present experiments performed on the q2DES formed at NiFe/LAO/STO and NiFe/(metal)/STO heterostructures. We investigating the nature of the inverse Edelstein effect (responsible for the spin-to-charge conversion) through a combination of spin pumping, magnetotransport, spectroscopy and gating experiments. We found a highly efficient spin-to-charge conversion which is tunable by a gate voltage. Results were then interpreted in terms of a crossover between the occupancy of one to several bands with different orbital characters and different spin-orbit textures.