CPM Seminar

Theoretical analysis of the transmission phase shift of a quantum dot in presence of Kondo correlations

P. Vitushinsky

CEA Grenoble

We study the effects of Kondo correlations on the transmission phase shift of a quantum dot coupled to two leads. Experimental determination of the phase shift made by embedding a quantum dot in one of the arms of a Aharonov-Bohm interferometer leads to a value of the phase which differs from the well-known theoretical predictions. We propose here a theoretical interpretation of these results based on scattering theory combined with Bethe ansatz calculations. Quantitative agreement is obtained with experimental results for two different values of the coupling to the leads. We also propose an explanation for the unexpected phase lapses observed in the Coulomb Blockade and Kondo regimes.