High-Efficiency Long-Spin-Coherence Electrical Spin Injection in CoFe/InGaAs Two-Dimensional Electron Gas Lateral Spin-Valve Devices

Electrical spin injection experiments are performed at 1.5 K in a new hybrid structure, In0.75Ga0.25As two-dimensional electron gases with lateral Co0.8Fe0.2 electrodes. From the electrode spacing (less than or similar to 9 mu m) dependence of the spin-valve signals in the nonlocal regime, we obtained very promising results such as longer spin diffusion length L-s of similar to 5.1 mu m and higher spin polarization eta of similar to 5.7% than those in former reports. They are mainly attained by the suppression of the D'yakonov-Perel' spin relaxation process due to the tuned spin-orbit couplings. (C) 2012 The Japan Society of Applied Physics