Berlin 2012 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 71: [MA] Joint Session "Graphen: Spin Transport" (jointly with DS, DY, HL, O, TT)
O 71.1: Topical Talk
Donnerstag, 29. März 2012, 15:00–15:30, H 1012
Spin transport in graphene — •Bernd Beschoten — II. Institute of Physics, RWTH Aachen University and JARA: Fundamentals of Future Information Technology, 52074 Aachen
Graphene is considered as promising candidate for spintronics applications. The reason is the weak spin-orbit coupling, the absent hyperfine interaction and the observation of micrometer long spin relaxation lengths [1]. So far most spin transport studies have focused on single layer graphene (SLG). However, bilayer graphene (BLG) has unique electronic properties, which differ greatly from those of SLG by its effective mass of carriers, interlayer hopping and electric-field induced band gap. Our studies of spin transport in BLG as a function of mobility µ, minimum conductivity, charge carrier density and temperature reveal the importance of the D’yakonov - Perel’ (DP)-type spin scattering mechanism [2]. In BLG samples, the spin relaxation time τs scales inversely with µ both at room temperature and at low temperatures. τs times of up to 2 ns are observed in samples with the lowest mobility. We discuss the role of intrinsic and extrinsic factors that could lead to the dominance of the DP-type spin scattering mechanism in BLG. Remarkably, similar spin transport properties are also observed in large area graphene grown by the CVD method on copper foils demonstrating the potential of CVD graphene in spintronics devices [3].
Work supported by DFG/FOR 912.
[1] N. Tombros et al., Nature 448, 571 (2007).
[2] T.-Y. Yang et al., Phys. Rev. Lett. 107, 047206 (2011).
[3] A. Avsar et al., Nano Letters 11, 2363 (2011).