ABSTRACT
The spin injection and detection limitations posed by conductivity and lifetime mismatch between semiconductors and ferromagnetic (FM) metals [1–4] has been variously solved by lifting the constraints of ohmic transport with the insertion of a tunnel barrier [5, 6] or the use of ferromagnetic semiconductors [7, 8]. However, for many semiconductors, there are additional materials-dependent obstacles to the observation of spin transport. The materials properties of elemental group-IV semiconductors silicon (Si) and germanium (Ge), pose problems such as alloy formation at metallic contacts and difficulties with the use of optical methods for spin detection due to indirect bandgap [9, 10].
