Information Processing with Pure Spin Currents in Silicon: Spin Injection, Extraction, Manipulation and Detection

IEEE Transactions on Electron Devices, Vol. 56, No 10, p. 2343 Oct 2009 We demonstrate that information can be transmitted and processed with pure spin currents in silicon. Fe/Al2O3 tunnel barrier contacts are used to produce significant electron spin polarization in the silicon, generating a spin current which flows outside of the charge current path. The spin orientation of this pure spin current is controlled in one of three ways: (a) by switching the magnetization of the Fe contact, (b) by changing the polarity of the bias on the Fe/Al2O3 (injector) contact, which enables the generation of either majority or minority spin populations in the Si, providing a way to electrically manipulate the injected spin orientation without changing the magnetization of the contact itself, and (c) by inducing spin precession through application of a small perpendicular magnetic field. Spin polarization by electrical extraction is as effective as that achieved by the more common electrical spin injection. The output characteristics of a planar silicon three terminal device are very similar to those of non-volatile giant magnetoresistance metal spin-valve structures