Electrical injection and detection of spin-polarized electrons in silicon through an Fe3Si/Si Schottky tunnel barrier

Abstract

We demonstrate electrical injection and detection of spin-polarized electrons in silicon (Si) using epitaxially grown ${\text{Fe}}_3\text{Si}/\text{Si}$ Schottky-tunnel-barrier contacts. By an insertion of a $\delta$ -doped $n^{+}\text{-Si}$ layer $\left(\sim {10}^{19}{\text{cm}}^{-3}\right)$ near the interface between a ferromagnetic ${\text{Fe}}_3\text{Si}$ contact and a Si channel $\left(\sim {10}^{15}{\text{cm}}^{-3}\right)$ , we achieve a marked enhancement in the tunnel conductance for reverse-bias characteristics of the ${\text{Fe}}_3\text{Si}/\text{Si}$ Schottky diodes. Using laterally fabricated four-probe geometries with the modified ${\text{Fe}}_3\text{Si}/\text{Si}$ contacts, we detect nonlocal output signals that originate from the spin accumulation in a Si channel at low temperatures.