title: Tunable transmission of quantum Hall edge channels with full degeneracy lifting in split-gated graphene devices.
abstract: Charge carriers in the quantum Hall regime propagate via one-dimensional conducting channels that form along the edges of a two-dimensional electron gas. Controlling their transmission through a gate-tunable constriction, also called quantum point contact, is fundamental for many coherent transport experiments. However, in graphene, tailoring a constriction with electrostatic gates remains challenging due to the formation of p-n junctions below gate electrodes along which electron and hole edge channels co-propagate and mix, short circuiting the constriction. Here we show that this electron-hole mixing is drastically reduced in high-mobility graphene van der Waals heterostructures thanks to the full degeneracy lifting of the Landau levels, enabling quantum point contact operation with full channel pinch-off. We demonstrate gate-tunable selective transmission of integer and fractional quantum Hall edge channels through the quantum point contact. This gate control of edge channels opens the door to quantum Hall interferometry and electron quantum optics experiments in the integer and fractional quantum Hall regimes of graphene.
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Katrin
authors.initials: K
authors.lastname: Zimmermann
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Jordan
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gay
authors.affiliation: Advanced Materials Laboratory, National, Institute for Materials Science, 1-1 Namiki, Tsukuba 305, Japan.
authors.forename: Kenji
authors.identifier: 0000-0003-3701-8119
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Advanced Materials Laboratory, National, Institute for Materials Science, 1-1 Namiki, Tsukuba 305, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Han
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Bouchiat
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Hermann
authors.initials: H
authors.lastname: Sellier
authors.affiliation: Univ. Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Sacépé