Quantification of Spin Drift in Devices with a Heavily Doped Si Channel

The development of practical silicon spintronic devices relies on a comprehensive understanding of the spin-transport properties of the silicon channel. When the drift electric field in the channel is small, spin transport is described well by spin diffusion alone, but at larger fields spin drift starts to play a role. The authors present a simple, general, accurate method to quantify spin drift in nonlocal spin-transport devices, showing that in heavily doped Si, drift electric fields of \ifmmode\pm\else\textpm\fi{}400 V/cm increase or reduce the spin-transport length by about a factor of two. Such quantification of spin drift is important for correct assessment of device characteristics and performance.