Regensburg 2013 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 40: Poster Session Correlated Electrons

TT 40.4: Poster

Mittwoch, 13. März 2013, 15:00–19:00, Poster D

Hybrid NRG-DMRG approach to real-time dynamics of quantum impurity systems — •Fabian Güttge and Frithjof B. Anders — Technische Universität Dortmund, Lehrstuhl für Theoretische Physik II, 44221 Dortmund, Germany

We present a non-equilibrium hybrid method which uses the numerical renormalization group (NRG) to generate an effective low energy Hamiltonian. This Hamiltonian is then solved with the density-matrix renormalization group (DMRG). By considering systems with two Wilson chains patched together we reduce discretization errors. As the NRG reduces the effective bandwidth of the system the time scales accessible by the DMRG are exponentially increased. We employ the hybrid method to simulate the real-time dynamics of the interacting resonant level model (IRLM) after a sudden local quench. For U=0 the method recovers the exact results. In the limit U→∞ we compare the hybrid method results to results obtained by a strong coupling treatment of the IRLM. We find an excellent agreement. Furthermore, the hybrid method is capable of treating the IRLM in the whole parameter regime.