Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 79: Correlated Electrons - Poster Session

TT 79.28: Poster

Wednesday, April 2, 2014, 15:00–19:00, P2

The Numerical Renormalization Group as impurity solver within the Dynamical Mean-Field - Theory for multi-band lattice models — •Katharina Stadler, Andreas Weichselbaum, and Jan von Delft — Physics Department, Arnold Sommerfeld Center for Theoretical Physics and Center of NanoScience, Ludwig-Maximilians-Universität, Munich, Germany

Dynamical Mean-Field Theory (DMFT) provides a non-perturbative many-body approach to describe the local dynamics of strongly correlated materials by mapping a lattice model self-consistently onto an effective quantum impurity model, which is then solved by a non-perturbative method, such as Quantum Monte Carlo simulations (QMC) or the Numerical Renormalization Group (NRG) approach.

Here, we use NRG as DMFT impurity solver to treat multi-band models. Typically, the application of NRG in this context is strongly limited since the numerical cost increases exponentially with the number of bands. To deal with this limitation, we investigate two strategies: First, for multi-band models with intrinsic symmetries, we implement these explicitly in our numerical code using non-abelian channel symmetries [1] where applicable. Second, for models without symmetries we investigate the feasibility of using interleaved Wilson chains, as recently proposed [2]. We also test the reliability of the latter method by applying it to models with symmetries and comparing the results to those obtained by the explicit treatment of the non-abelian channel symmetry.
A. Weichselbaum, Ann.Phys. (N.Y.) 327, 2012
A. K. Mitchell et al., arXiv:1308.1903