title: Transmission phase in the Kondo regime revealed in a two-path interferometer.
abstract: We report on the direct observation of the transmission phase shift through a Kondo correlated quantum dot by employing a new type of two-path interferometer. We observed a clear π/2-phase shift, which persists up to the Kondo temperature TK. Above this temperature, the phase shifts by more than π/2 at each Coulomb peak, approaching the behavior observed for the standard Coulomb blockade regime. These observations are in remarkable agreement with two-level numerical renormalization group calculations. The unique combination of experimental and theoretical results presented here fully elucidates the phase evolution in the Kondo regime.
authors.affiliation: Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takada
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France and CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: C
authors.initials: C
authors.lastname: Bäuerle
authors.affiliation: Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan and PRESTO, JST, Kawaguchi-shi, Saitama 331-0012, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France and CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: S
authors.initials: S
authors.lastname: Hermelin
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France and CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: T
authors.initials: T
authors.lastname: Meunier
authors.affiliation: Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 München, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Alex
authors.affiliation: Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 München, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Weichselbaum
authors.affiliation: Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 München, Germany.
authors.forename: J
authors.initials: J
authors.lastname: von Delft
authors.affiliation: Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Ludwig
authors.affiliation: Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
authors.forename: A D
authors.initials: AD
authors.lastname: Wieck
authors.affiliation: Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan and RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako-shi, Saitama 31-0198, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tarucha