Regensburg 2022 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 29: 2D Materials: Graphene
HL 29.5: Vortrag
Donnerstag, 8. September 2022, 10:30–10:45, H36
Anisotropic transport in 1D graphene superlattices — •Julia Amann1, Kenji Watanabe2, Takashi Taniguchi2, Dieter Weiss1, and Jonathan Eroms1 — 1Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany — 2National Institute for Materials Science, Tsukuba, Japan
One-dimensional superlattices (1DSL) in graphene were predicted to show intriguing effects, such as anisotropy in transport, additional Dirac points and a distorted Fermi contour. In contrast to two-dimensional graphene superlattices, which have been widely studied, only very few experiments on graphene 1DSLs have been reported. We use a patterned few-layer graphene gate underneath an encapsulated monolayer graphene to create a 1DSL. With the combined action of a global silicon backgate and the patterned bottom gate we are able to control superlattice potential strength and charge carrier density independently. We show low temperature transport measurements on a gate tunable 1DSL in graphene with a period of 50 nm in directions parallel and perpendicular to the modulation as we use an L-shaped Hall bar. The typical Dirac cone shape gets distorted, and we observe anisotropic transport in x and y direction. We observe the emergence of multiple Dirac points in modulation direction due to band flattening with increasing superlattice potential. These extra Dirac points are represented as additional Landau fans in magnetotransport. Further, Weiss oscillations can be observed which confirm the 1D superlatice modulation and the anisotropy.