Hanle-effect measurements of spin injection from Mn₅Ge₃C_0.8/Al₂O₃-contacts into degenerately doped Ge channels on Si

We report electrical spin injection and detection in degenerately doped n-type Ge channels using Mn₅Ge₃C_0.8/Al₂O₃/n⁺-Ge tunneling contacts for spin injection and detection. The whole structure is integrated on a Si wafer for complementary metal-oxide-semiconductor compatibility. From three-terminal Hanle-effect measurements, we observe a spin accumulation up to 10 K. The spin lifetime is extracted to be 38 ps at T = 4 K using Lorentzian fitting, and the spin diffusion length is estimated to be 367 nm due to the high diffusion coefficient of the highly doped Ge channel.