Evidence of Electrical Spin Injection Into Silicon Using MgO Tunnel Barrier

We demonstrate the evidence of electrical spin injection into silicon (Si) using the Fe/MgO tunnel barrier by the following two methods: 1) non-local (NL) four-terminal magnetoresistance (MR) scheme with their respective corresponding ferromagnetic (FM) electrode and 2) Hanle-type spin precession scheme. These results are compatible and in agreement with each other. The spin injection signals in the non-local scheme were observed up to 150 K, and the spin diffusion length (lambda(N)) was estimated to be 2.8 mu m at 8 K. The experimental data completely matches every detail of the Hanle measurements equation, and spin lifetime (tau) was estimated to be 9.44 ns at 8 K. We will be able to discuss the physical properties of a pure spin current in silicon by this compelling data.