AVS 56th International Symposium & Exhibition
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI+EM-WeA

Invited Paper MI+EM-WeA9
Electrical Injection, Detection and Modulation of Spin Currents in Silicon

Wednesday, November 11, 2009, 4:40 pm, Room C1

Session: Magnetism and Spin Injection in Semiconductors
Presenter: O.M.J. van 't Erve, Naval Research Laboratory
Authors: O.M.J. van 't Erve, Naval Research Laboratory
C. Awo-Affouda, Naval Research Laboratory
A.T. Hanbicki, Naval Research Laboratory
M.A. Holub, Naval Research Laboratory
C.H. Li, Naval Research Laboratory
P.E. Thompson, Naval Research Laboratory
B.T. Jonker, Naval Research Laboratory
Correspondent: Click to Email
The electron’s spin angular momentum is one of several alternative state variables under consideration on the International Technology Roadmap for Semiconductors for processing information in the fundamentally new ways. Significant progress has recently been made on spin injection into the technologically important semiconductor, Si, using vertical device structures. Here we will present the electrical injection, detection and magnetic field modulation of lateral diffusive spin transport through silicon using Fe/Al2O3 surface contacts. The tunnel contacts are used to create and analyze the flow of pure spin current in a silicon transport channel. A nonlocal detection technique has been used to exclude spurious contributions from AMR and local Hall effects. The nonlocal signal shows that a spin current can be electrically detected after diffusive transport through the silicon transport channel and the signal depends on the relative orientation of the magnetization of the injecting and detecting contacts. Hanle effect measurements up to 125 K demonstrate that the spin current can be modulated by a perpendicular magnetic field, which causes the electron spin to precess and dephase in the channel during transport. By changing the bias on the injector contact we can either inject or extract spin from the Silicon channel. Here we will show using Hanle and lateral spin-valve measurements that we can change the polarization of the spin accumulation by going from the injection regime to the extraction regime and we will compare the efficiency of spin-injection versus spin extraction.

The realization of efficient electrical injection and detection using tunnel barriers and a simple device geometry compatible with "back-end" Si processing should greatly facilitate development of Si-based spintronics.

This work was supported by ONR and core NRL programs.