title: Long Spin Diffusion Length in Few-Layer Graphene Flakes.
abstract: We report a spin valve with a few-layer graphene flake bridging highly spin-polarized La_{0.67}Sr_{0.33}MnO_{3} electrodes, whose surfaces are kept clean during lithographic definition. Sharp magnetic switching is verified using photoemission electron microscopy with x-ray magnetic circular dichroism contrast. A naturally occurring high interfacial resistance ∼12  MΩ facilitates spin injection, and a large resistive switching (0.8  MΩ at 10 K) implies a 70-130  μm spin diffusion length that exceeds previous values obtained with sharp-switching electrodes.
authors.affiliation: Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, United Kingdom.
authors.forename: W
authors.initials: W
authors.lastname: Yan
authors.affiliation: Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, United Kingdom.
authors.forename: L C
authors.initials: LC
authors.lastname: Phillips
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Barbone
authors.affiliation: NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto, Finland.
authors.forename: S J
authors.initials: SJ
authors.lastname: Hämäläinen
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Lombardo
authors.affiliation: Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, United Kingdom.|DiFeST, University of Parma, viale G.P. Usberti 7/A, 43124 Parma, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Ghidini
authors.affiliation: Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, United Kingdom.
authors.forename: X
authors.initials: X
authors.lastname: Moya
authors.affiliation: Diamond Light Source, Chilton, Didcot, Oxfordshire OX11 0DE, United Kingdom.
authors.forename: F
authors.initials: F
authors.lastname: Maccherozzi
authors.affiliation: NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto, Finland.
authors.forename: S
authors.initials: S
authors.lastname: van Dijken
authors.affiliation: Diamond Light Source, Chilton, Didcot, Oxfordshire OX11 0DE, United Kingdom.
authors.forename: S S
authors.initials: SS
authors.lastname: Dhesi
authors.affiliation: Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
authors.forename: A C
authors.initials: AC
authors.lastname: Ferrari
authors.affiliation: Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, United Kingdom.
authors.forename: N D
authors.initials: ND
authors.lastname: Mathur