Recent studies in orbitronics have found large current-induced torques originating—in the current

understanding—from incident orbital currents. These can be generated by the orbital Rashba-Edelstein

effect (OREE) produced at the interface between some light metals and their oxide films, e.g., by a

naturally oxidized copper layer (Cu∗). In the present work, using second-harmonic Hall techniques, we

determine the ratio of orbital vs spin currents exerting torques on thin transition-metal Co ferromagnets

in systems using an orbit-to-spin Pt converter as an interlayer with Cu∗. Our results quantifying dampinglike

torques show that both orbital and spin contributions are enhanced in these systems. Moreover, the

experimental determination of the decoherence length in a sample series with varying Co thickness clearly

demonstrates the interfacial generation of the orbital currents in Cu∗ by the OREE, leading to subsequent

magnetic torque in Co over a typical length scale of several nanometers.

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