Cu2O as a nonmagnetic semiconductor for spin transport in crystalline oxide electronics

We probe spin transport in Cu2O by measuring spin-valve effect in La0.7Sr0.3MnO3/Cu2O/Co and La0.7Sr0.3MnO3/Cu2O/La0.7Sr0.3MnO3 epitaxial heterostructures. In La0.7Sr0.3MnO3/Cu2O/Co systems, we find that a fraction of out-of-equilibrium spin-polarized carrier actually travel across the Cu2O layer up to distances of almost 100 nm at low temperature. The corresponding spin-diffusion length d(spin) is estimated around 40 nm. Furthermore, we find that the insertion of a SrTiO3 tunneling barrier does not improve spin injection, likely due to the matching of resistances at the interfaces. Our result on d(spin) may be likely improved, both in terms of Cu2O crystalline quality and submicrometric morphology and in terms of device geometry, indicating that Cu2O is a potential material for efficient spin transport in devices based on crystalline oxides.