title: Electron Phase Shift at the Zero-Bias Anomaly of Quantum Point Contacts.
abstract: The Kondo effect is the many-body screening of a local spin by a cloud of electrons at very low temperature. It has been proposed as an explanation of the zero-bias anomaly in quantum point contacts where interactions drive a spontaneous charge localization. However, the Kondo origin of this anomaly remains under debate, and additional experimental evidence is necessary. Here we report on the first phase-sensitive measurement of the zero-bias anomaly in quantum point contacts using a scanning gate microscope to create an electronic interferometer. We observe an abrupt shift of the interference fringes by half a period in the bias range of the zero-bias anomaly, a behavior which cannot be reproduced by single-particle models. We instead relate it to the phase shift experienced by electrons scattering off a Kondo system. Our experiment therefore provides new evidence of this many-body effect in quantum point contacts.
authors.affiliation: Université Grenoble Alpes, F-38000 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: B
authors.initials: B
authors.lastname: Brun
authors.affiliation: IMCN/NAPS, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Martins
authors.affiliation: IMCN/NAPS, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Faniel
authors.affiliation: IMCN/NAPS, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Hackens
authors.affiliation: CNRS, Laboratoire de Photonique et de Nanostructures, UPR20, F-91460 Marcoussis, France.
authors.forename: A
authors.initials: A
authors.lastname: Cavanna
authors.affiliation: CNRS, Laboratoire de Photonique et de Nanostructures, UPR20, F-91460 Marcoussis, France.
authors.forename: C
authors.initials: C
authors.lastname: Ulysse
authors.affiliation: CNRS, Laboratoire de Photonique et de Nanostructures, UPR20, F-91460 Marcoussis, France.
authors.forename: A
authors.initials: A
authors.lastname: Ouerghi
authors.affiliation: CNRS, Laboratoire de Photonique et de Nanostructures, UPR20, F-91460 Marcoussis, France.
authors.forename: U
authors.initials: U
authors.lastname: Gennser
authors.affiliation: CNRS, Laboratoire de Photonique et de Nanostructures, UPR20, F-91460 Marcoussis, France.
authors.forename: D
authors.initials: D
authors.lastname: Mailly
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, F-91405 Orsay, France.
authors.forename: P
authors.initials: P
authors.lastname: Simon
authors.affiliation: Université Grenoble Alpes, F-38000 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: S
authors.initials: S
authors.lastname: Huant
authors.affiliation: Université Grenoble Alpes, F-38000 Grenoble, France.|IMCN/NAPS, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Bayot
authors.affiliation: Université Grenoble Alpes, F-38000 Grenoble, France.|CEA, INAC-SPSMS, F-38054 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Sanquer
authors.affiliation: Université Grenoble Alpes, F-38000 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: H
authors.initials: H
authors.lastname: Sellier