Electrical injection and detection of spin-polarized electrons in silicon through an Fe₃ Si/Si Schottky tunnel barrier

We demonstrate electrical injection and detection of spin-polarized electrons in silicon (Si) using epitaxially grown Fe₃ Si/Si Schottky-tunnel-barrier contacts. By an insertion of a δ -doped n ⁺ -Si layer (∼ 10¹⁹ cm^-3) near the interface between a ferromagnetic Fe₃ Si contact and a Si channel (∼ 10¹⁵ cm^-3), we achieve a marked enhancement in the tunnel conductance for reverse-bias characteristics of the Fe₃ Si/Si Schottky diodes. Using laterally fabricated four-probe geometries with the modified Fe₃ Si/Si contacts, we detect nonlocal output signals that originate from the spin accumulation in a Si channel at low temperatures.