Coulomb Interaction Effect in Quantum Transport

We study the quantum Anderson model in the presence of the finite Coulomb interaction U using the t-matrix approximation. The energy of the d-electron level increases as Uln (U/πΔ) for strong Coulomb interaction U and finite level-width Δ. In the case of small U/Δ parameter this approximation gives the results from the perturbation theory. The spin susceptibility is calculated as a function of U and compared with the results obtained by renormalized perturbation approximation. The results can be used to study the effect of the finite Coulomb interaction in the quantum transport.