Observation of Magnetoresistance Caused by Orbital Angular Momentum Accumulation

We report a sizable angular dependent magnetoresistance (ADMR) in a Tm 3 Fe 5 O 12 /oxidized Cu (CuO x ) heterostructure, which cannot be attributed to the spin Hall magnetoresistance in lack of elements with large spin-orbit coupling. Different from the orbital Rashba-Edelstein magnetoresistance proposed previously, the ADMR depends on the magnitude of magnetic field rather than the magnetization of magnetic layer. Based on contrast experiment, we conclude that the ADMR originates from the electrically induced orbital angular momentum (OAM) accumulating at the interface of insulator/CuO x. Our findings not only reveal the transmission and accumulation of OAM in insulator/CuO x heterojunction but also provide important experimental evidences towards the microscopic understanding of the OAM interaction with magnetic field.