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

TL;DR

This paper investigates Fano resonance phenomena in electronic transport through a quantum wire with a side-coupled quantum dot, using the X-boson method to analyze the Anderson impurity model in the infinite U limit.

Contribution

It introduces the application of the X-boson approach to study Fano resonance in a quantum wire with a side quantum dot, capturing the crossover from mixed-valence to Kondo regimes.

Findings

Conductance shows a minimum at T=0 due to destructive interference.

Resonance exhibits Fano behavior consistent with experiments.

Conductance temperature dependence is logarithmic and universal.

Abstract

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=\infty $. 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.