Spin lifetime in silicon in the presence of parasitic electronic effects

Abstract

A hybrid ferromagnet/semiconductor device is used to determine a lower bound on the spin lifetime for conduction electrons in silicon. We use spin precession to self-consistently measure the drift velocity versus drift field of spin-polarized electrons, and use this electronic control to change the transit time between electron injection and detection. A measurement of normalized magnetocurrent as a function of drift velocity is used with a simple exponential-decay model to argue that the value obtained (≈2 ns) is artificially lowered by electronic effects and could potentially be orders of magnitude higher.