Kondo effect in complex mesoscopic structures

We study the Kondo effect of a quantum dot placed in a complex mesoscopic structure. Assuming that electronic interactions are taking place solely on the dot, and focusing on the infinite Hubbard interaction limit, we use a decoupling scheme to obtain an explicit analytic approximate expression for the dot Green function, which satisfies certain Fermi-liquid relations at zero temperature. The details of the complex structure enter into this expression only via the self-energy for the noninteracting case. The effectiveness of the expression is demonstrated for the single-impurity Anderson model and for the T-shaped network.