Abstract
We apply the adaptive time-dependent density-matrix renormalization-group method tDMRG to the study
of transport properties of quantum-dot systems connected to metallic leads. Finite-size effects make the usual
tDMRG description of the Kondo regime a numerically demanding task. We show that such effects can be
attenuated by describing the leads by “Wilson chains,” in which the hopping matrix elements decay exponentially
away from the impurity tn−n/2. For a given system size and in the linear-response regime, results for
1 show several improvements over the undamped =1 case: perfect conductance is obtained deeper in the
strongly interacting regime and current plateaus remain well defined for longer time scales. Similar improvements
were obtained in the finite-bias regime up to bias voltages of the order of the Kondo temperature. These
results show that with the proposed modification, the tDMRG characterization of Kondo correlations in the
transport properties can be substantially improved, while it turns out to be sufficient to work with much smaller
system sizes. We discuss the numerical cost of this approach with respect to the necessary system sizes and the
entanglement growth during the time evolution.
