title: Spin-Dependent Transport in Fe/GaAs(100)/Fe Vertical Spin-Valves.
abstract: The integration of magnetic materials with semiconductors will lead to the development of the next spintronics devices such as spin field effect transistor (SFET), which is capable of both data storage and processing. While the fabrication and transport studies of lateral SFET have attracted greatly attentions, there are only few studies of vertical devices, which may offer the opportunity for the future three-dimensional integration. Here, we provide evidence of two-terminal electrical spin injection and detection in Fe/GaAs/Fe vertical spin-valves (SVs) with the GaAs layer of 50 nanometers thick and top and bottom Fe electrodes deposited by molecular beam epitaxy. The spin-valve effect, which corresponds to the individual switching of the top and bottom Fe layers, is bias dependent and observed up to 20 K. We propose that the strongly bias- and temperature-dependent MR is associated with spin transport at the interfacial Fe/GaAs Schottky contacts and in the GaAs membranes, where balance between the barrier profiles as well as the dwell time to spin lifetime ratio are crucial factors for determining the device operations. The demonstration of the fabrication and spin injection in the vertical SV with a semiconductor interlayer is expected to open a new avenue in exploring the SFET.
authors.affiliation: York-Nanjing Joint Center in Spintronics and NanoEngineering, School of Electronics Science and Engineering, Nanjing University, Nanjing 210093, China.|Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, YO10 5DD, UK.
authors.forename: P K Johnny
authors.initials: PK
authors.lastname: Wong
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, YO10 5DD, UK.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Physics, University of York, YO10 5DD, UK.
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, YO10 5DD, UK.
authors.forename: Iain G
authors.initials: IG
authors.lastname: Will
authors.affiliation: York-Nanjing Joint Center in Spintronics and NanoEngineering, School of Electronics Science and Engineering, Nanjing University, Nanjing 210093, China.|Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, YO10 5DD, UK.
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Physics, Beijing Normal University, Beijing, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Xia
authors.affiliation: Toshiba Research Europe Limited, Cambridge Research Laboratory, 260 Cambridge Science Park, Milton Road, Cambridge, CB4 0WE, UK.
authors.forename: Stuart N
authors.initials: SN
authors.lastname: Holmes
authors.affiliation: Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Farrer
authors.affiliation: Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge, CB3 0HE, UK.
authors.forename: Harvey E
authors.initials: HE
authors.lastname: Beere
authors.affiliation: Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge, CB3 0HE, UK.
authors.forename: Dave A
authors.initials: DA
authors.lastname: Ritchie