title: Highly spin-polarized room-temperature tunnel injector for semiconductor spintronics using MgO(100).
abstract: The spin polarization of current injected into GaAs from a CoFe/MgO(100) tunnel injector is inferred from the electroluminescence polarization from GaAs/AlGaAs quantum well detectors. The polarization reaches 57% at 100 K and 47% at 290 K in a 5 T perpendicular magnetic field. Taking into account the field dependence of the luminescence polarization, the spin injection efficiency is at least 52% at 100 K, and 32% at 290 K. We find a nonmonotonic temperature dependence of the polarization which can be attributed to spin relaxation in the quantum well detectors.
authors.affiliation: IBM Research Division, Almaden Research Center, San Jose, California 95120, USA.
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: R
authors.initials: R
authors.lastname: Wang
authors.forename: R M
authors.initials: RM
authors.lastname: Shelby
authors.forename: R M
authors.initials: RM
authors.lastname: Macfarlane
authors.forename: S R
authors.initials: SR
authors.lastname: Bank
authors.forename: J S
authors.initials: JS
authors.lastname: Harris
authors.forename: S S P
authors.initials: SS
authors.lastname: Parkin