Observation of the orbital inverse Rashba–Edelstein effect

The spin–orbit interaction plays an important role in magnetism and in many quantum materials. It is the cornerstone of the physics of many electronic phases that emerge at interfaces because of broken inversion symmetry. In that context, the spin Rashba effect locks electronic spins with momentum to produce large spin galvanic effects. It has recently been argued that these spin-based effects could in fact be spin–orbit coupling consequences of a potentially larger orbital effect. Here we observe spin-to-charge conversion at a LaAlO3/SrTiO3 interface and demonstrate that its orbital contribution dominates. Our analysis of the in-plane anisotropy and gate voltage dependence of the angular momentum conversion into charge highlights some of the salient features of the orbital Rashba splitting. These results open the door to broader use of pure orbital angular momentum effects and confirm the potential of the orbital degree of freedom for information storage and processing.