AVS 58th Annual International Symposium and Exhibition
    Graphene and Related Materials Focus Topic Tuesday Sessions
       Session GR+MI-TuA

Paper GR+MI-TuA3
Electron Spin Transport in Exfoliated and Epitaxial Graphene Grown on SiC

Tuesday, November 1, 2011, 2:40 pm, Room 208

Session: Graphene: Magnetic Properties and Spin-Dependent Phenomena
Presenter: Joseph Abel, University at Albany
Authors: J. Abel, University at Albany
A. Matsubayashi, University at Albany
J.J. Garramone, University at Albany
C. Dimitrakopoulos, IBM T.J. Watson Research Center
A. Grill, IBM T.J. Watson Research Center
Sung, IBM T.J. Watson Research Center
V.P. LaBella, University at Albany
Correspondent: Click to Email
Graphene is an ideal candidate for the transport channel in future spintronic devices due to its long spin lifetimes at room temperature. The long lifetime arises due to the small intrinsic spin orbit coupling and low hyper-fine interaction of the electron spins with the carbon nuclei. Non-local Hanle measurement devices were fabricated on epitaxially grown graphene on SiC, provided by IBM, and multi-layer exfoliated flakes. Spin injection and detection were achieved in these devices using cobalt nano-magnets directly deposited on the graphene. Spin precession was observed and the spin lifetimes for the epitaxial graphene were found to be comparable to those found in the exfoliated multi-layer flake. We will also present our measurements of spin relaxation as a function of temperature. The temperature dependence in the spin lifetime observed in the exfoliated flake show a coupling between the magnetic contacts and graphene channel. This is expected due to the lack of a tunnel barrier contact. The comparable spin relaxation times measured in epitaxial graphene fabricated with similar contacts and the multi-layer flake is believed to be caused by a large contact induced relaxation due to the contacts coupling with the graphene channel. The strong coupling effectively removes the spin from the channel.