Room temperature gate tunable spin-to-charge conversion in LaCrO3/SrTiO3 heterostructures

Abstract

The recent emergence of novel spintronics studies focuses on the generation, transmission, and control of a pure spin current through spin-orbit effects by converting the pure spin current into the charge current or vice versa. The emergence of novel electronic and magnetic phenomena at the interfaces between polar and non-polar crystalline transition metal complex oxides such as high mobility two-dimensional electron gases (2DEG) provides an ideal platform for the design of spin-to-charge (StC) convertors. At these interfaces, an interface-driven spin-orbit coupling mechanism - the Rashba effect - shows great promise due to its unprecedented StC interconversion efficiency, so-called inverse Rashba-Edelstein effect (IREE). Here we report a new type of 2DEG formed at the interface between the antiferromagnetic LaCrO3 and insulating SrTiO3 heterostructure with efficient StC conversion efficiency. The measured IREE length is up to 0.3 nm which can be modulated by a gate voltage. The frequency and field orientation dependence of IREE response are both consistent with the spin pumping model, from which the spin relaxation time (~30ps) is derived. Our findings launch a new class of oxide-based 2DEGs for future spin orbitronic applications. Device preparation was partially supported by ECCS-1933297 and NC State-Nagoya Collaboration Grant. Sample growth was supported by NSF DMR-1751455.