Electrical detection of spin transport in lateral ferromagnet-semiconductor devices

The development of semiconductor spintronics requires a reliable electronic means for writing, processing and reading information using spin-polarized carriers. Here, we demonstrate a fully electrical scheme for achieving spin injection, transport and detection in a single device. Our device consists of a lateral semiconducting channel with two ferromagnetic contacts, one of which serves as a source of spin-polarized electrons and the other as a detector. Spin detection in the device is achieved through a non-local, spin-sensitive, Schottky-tunnel-barrier contact whose electrochemical potential depends on the relative magnetizations of the source and detector. We verify the effectiveness of this approach by showing that a transverse magnetic field suppresses the non-local signal at the detection contact by inducing spin precession and dephasing in the channel ( the Hanle effect). The sign of the signal varies with the injection current and is correlated with the spin polarization in the channel as determined by optical Kerr rotation measurements.