Dresden 2009 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 46: Correlated Electrons: Quantum Impurities, Kondo Physics

TT 46.9: Talk

Friday, March 27, 2009, 12:30–12:45, HSZ 301

Using DMRG to Study Quantum Impurity Models with Time-Dependent Hamiltonians — •Cheng Guo¹, Andreas Weichselbaum¹, Stefan Kehrein¹, Tao Xiang², and Jan von Delft¹ — ¹Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität München, D-80333 München, Germany — ²Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, China

We use the adaptive time-dependent density matrix renormalization group method (t-DMRG) to study the nonequilibrium dynamics of a benchmark quantum impurity system which has a time-dependent Hamiltonian. This model is a resonant-level model, obtained by a mapping from a certain ohmic spin-boson model describing the dissipative Landau-Zener transition. Some techniques from the numerical renormalization group method (NRG) are borrowed to transform this model to a DMRG-friendly form. We compare t-DMRG results with exact results at zero temperature and find very good agreement. We also give a physical interpretation of the numerical results.