Fano resonance in electronic transport through a quantum wire with a side-coupled quantum dot:X-boson treatment

The transport through a quantum wire with a side-coupled quantum dot is studied. We use the X-boson treatment for the Anderson single impurity model in the limit of U=∞. The conductance presents a minimum for values of $T=0$ in the crossover from mixed valence to Kondo regime due to a destructive interference between the ballistic channel associated with the quantum wire and the quantum dot channel. We obtain the experimentally studied Fano behavior of the resonance. The conductance as a function of temperature exhibits a logarithmic and universal behavior, that agrees with recent experimental results.