Upstream modes and antidots poison graphene quantum Hall effect
RePEc: Research Papers in Economics
Abstract
Abstract The quantum Hall effect is the seminal example of topological protection, as charge carriers are transmitted through one-dimensional edge channels where backscattering is prohibited. Graphene has made its marks as an exceptional platform to reveal new facets of this remarkable property. However, in conventional Hall bar geometries, topological protection of graphene edge channels is found regrettably less robust than in high mobility semi-conductors. Here, we explore graphene quantum Hall regime at the local scale, using a scanning gate microscope. We reveal the detrimental influence of antidots along the graphene edges, mediating backscattering towards upstream edge channels, hence triggering topological breakdown. Combined with simulations, our experimental results provide further insights into graphene quantum Hall channels vulnerability. In turn, this may ease future developments towards precise manipulation of topologically protected edge channels hosted in various types of two-dimensional crystals.
Authors 6
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Affiliation as printed
IMCN/NAPS, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium
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Affiliation as printed
JARA-FIT and 2nd Institute of Physics—RWTH Aachen, Aachen, Germany
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National Institute for Materials Science
Affiliation as printed
Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
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National Institute for Materials Science
Affiliation as printed
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
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Affiliation as printed
JARA-FIT and 2nd Institute of Physics—RWTH Aachen, Aachen, Germany
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Affiliation as printed
IMCN/NAPS, Université catholique de Louvain (UCLouvain), Louvain-la-Neuve, Belgium