In this brief communication, the charge susceptibility, χc,imp, is calculated for the single impurity Anderson model in the Kondo regime with the density matrix renormalization group theory (DMRG). Excellent agreement with the Bethe-Ansatz (BA) results is found in the appropriate limit where the (effective) level broadening Γ☆ and the charging energy, U, are much smaller than the conduction electron bandwidth, D. Deviations occur for large interactions U>D, where we find that χc,imp decays faster, approximately by a factor D/U, as compared to the BA-prediction. Our work is of methodological relevance, e.g., for studies of the Kondo-effect in molecular systems, in the sense that it prepares treatments of (spinful) few-orbital models in the Kondo regime.
Charge susceptibility in Kondo systems at half filling: DMRG study
P. Schmitteckert and F. Evers