Non-ohmic spin transport in n-type doped silicon

We demonstrate the injection and transport of spin-polarized electrons through n-type doped silicon with in-plane spin valve and perpendicular magnetic-field spin precession and dephasing ("Hanle effect") measurements. A voltage applied across the transport layer is used to vary the confinement potential caused by conduction-band bending and to control the dominant transport mechanism between drift and diffusion. By modeling the transport in this device with a Monte Carlo scheme, we simulate the observed spin polarization and Hanle features, showing that the average transit time across the short Si transport layer can be controlled over four orders of magnitude with applied voltage. As a result, this modeling allows inference of a long electron-spin lifetime despite the short transit length.