Dresden 2014 – scientific programme
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MA: Fachverband Magnetismus
MA 54: Graphene: Bi- and multi-layers (with DY/DS/HL/O/TT)
MA 54.2: Talk
Friday, April 4, 2014, 09:45–10:00, POT 081
Study of the magnetoresistance of biased graphene bilayers — •Dmitri Smirnov1, Galina Y. Vasileva1,2, Yurij B. Vasilyev2, Pavel S. Alekseev2, Yurij L. Ivanov2, Hennrik Schmidt1, Alexander W. Heine1, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover — 2Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg
We demonstrate magnetotransport behaviour of bilayer graphene. In contrast to monolayer graphene, bilayer has a parabolic band structure with a zero band gap, which can be opened by applying an electrical field perpendicular to the samples [1]. One of the consequences of such a band structure is the coexistence of two different types of charge carriers with the Fermi energy placed near the charge neutrality point.
Several bilayer graphene samples with different electrical properties (charge neutrality point, mobility) have been investigated. A positive and negative magnetoresistance is observed for electrons and holes. We can show that that the positive magnetotransport can be described well with a two carrier Drude model which allows us a new approach to probe parameters of electrons and holes separately.
[1] McCann, E., and V. Fal’ko Phys. Rev. Lett. 96, 086805 (2006)