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 -phase shift, which persists up to the Kondo temperature . Above this temperature, the phase shifts by more than 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.
- Received 21 November 2013
DOI:https://doi.org/10.1103/PhysRevLett.113.126601
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