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Statut |
Confirmé |
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Série |
LPENS-MDQ |
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Domaines |
cond-mat |
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Date |
Lundi 30 Mars 2015 |
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Heure |
14:00 |
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Institut |
LPA |
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Salle |
room 236, 29 rue d’Ulm |
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Nom de l'orateur |
Sacépé |
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Prenom de l'orateur |
Benjamin |
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Addresse email de l'orateur |
benjamin [dot] sacepe [at] grenoble [dot] cnrs [dot] fr |
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Institution de l'orateur |
Institut Néel (CNRS-UJF, Grenoble) |
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Titre |
Quantum point contact in graphene in the quantum Hall regime |
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Résumé |
We present an experimental study of a gate-defined Quantum Point Contact (QPC) made on a high-mobility, ballistic graphene device. Unlike usual 2D electron gases that can be fully depleted by electrostatic gating, the semi-metal character of graphene leads to the formation of transparent p-n junctions beneath the gates that do not significantly modify the electron transport. In this talk I will show that, when the graphene is turned into the quantum Hall regime, it is possible to use the p-n junction as a guide for quantum Hall edge channels and therefore confine the electron transport into the QPC. Varying the split gate potential of the QPC indeed enables a continuous selection of the transmitted integer as well as fractional edge channels through the constriction. I will then discuss peculiarities occurring in the N=0 Laudau level, which await further theoretical inputs. |
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Numéro de preprint arXiv |
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Commentaires |
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Fichiers attachés |
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