Transmission phase of a singly occupied quantum dot in the Kondo regime

We report on the phase measurements on a quantum dot containing a single electron in the Kondo regime. Transport takes place through a single orbital state. Although the conductance is far from the unitary limit, we measure directly, for the first time, a transmission phase as theoretically predicte...

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Bibliographic Details
Published inPhysical review letters Vol. 100; no. 22; p. 226601
Main Authors Zaffalon, M, Bid, Aveek, Heiblum, M, Mahalu, D, Umansky, V
Format Journal Article
LanguageEnglish
Published United States 06.06.2008
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Summary:We report on the phase measurements on a quantum dot containing a single electron in the Kondo regime. Transport takes place through a single orbital state. Although the conductance is far from the unitary limit, we measure directly, for the first time, a transmission phase as theoretically predicted of pi/2. As the dot's coupling to the leads is decreased, with the dot entering the Coulomb blockade regime, the phase reaches a value of pi. Temperature shows little effect on the phase behavior in the range 30-600 mK, even though both the two-terminal conductance and amplitude of the Aharonov-Bohm oscillations are strongly affected. These results also suggest that previous phase measurements involved transport through more than a single level.
ISSN:0031-9007
DOI:10.1103/physrevlett.100.226601