Berlin 2015 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 3: Graphene: THz, NIR and transport properties (with O/TT)
HL 3.4: Vortrag
Montag, 16. März 2015, 10:15–10:30, ER 270
Magnetotransport in small angle twisted bilayers of folded graphene — •Johannes Rode1, Hennrik Schmidt1,2, Dmitri Smirnov1, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover — 2Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore
Naturally occurring double-layer graphene consists of two hexagonal lattices in Bernal-stacking, described by a translational displacement between layers. While this type of bilayer is most commonly studied, the introduction of a rotational mismatch opens up a whole new field of rich physics, especially at small interlayer twist[1,2]. We investigate magnetotransport measurements on twisted graphene bilayers, prepared by folding of single layers. These reveal a strong dependence on the twist angle, which can be estimated by means of sample geometry. At small rotation, superlattices with a wavelength in the order of 10 nm arise and are observed by friction atomic force microscopy. Magnetotransport measurements in this small-angle regime show the formation of satellite Landau fans, which are attributed to additional Dirac singularities in the band structure[3].
[1] Lopes dos Santos, J. M. B., Peres, N. M. R. & Castro Neto, A. H. Phys. Rev. Lett. 99, 256802.
[2] Mele, E. J. Phys. Rev. B 84, 235439.
[3] Schmidt, H., Rode, J. C., Smirnov, D. & Haug, R. J. Nat. Commun. (accepted, Nov. 2014).