Phase evolution of the electronic transmission through a Kondo correlated quantum dot

We study the scattering phase shift of the Kondo assisted transmission through a quantum dot (QD), considering a model that includes an additional non resonant channel transmission. To compute the phase evolution and the transmission amplitude of the QD, for different temperatures, we describe the QD employing the single Anderson impurity model in the limit of infinity Coulomb repulsion, within the X-boson approach. Our results are consistent with the development of an unusually large phase evolution at around pi in the Kondo valley, observed in recent experiments, and is consistent with others theoretical treatments.