Regensburg 2013 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 40: Poster Session Correlated Electrons
TT 40.6: Poster
Mittwoch, 13. März 2013, 15:00–19:00, Poster D
Towards a Numerical Renormalization Group description of the steady-state nonequilibrium single-impurity Anderson model using Lindblad driving — •Frauke Schwarz1, Ireneusz Weymann2, Andreas Weichselbaum1, and Jan von Delft1 — 1Physics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universität, Munich — 2Institute of Physics, Adam Mickiewicz University, Poznań
Wilson’s Numerical Renormalization Group (NRG) allows to describe the single-impurity Anderson model (SIAM) in equilibrium in a non-perturbative way.
However, treating situations of steady-state nonequilibrium, such as transport through a quantum dot at finite source-drain bias,
remains a challenge for NRG. To model such situations, we consider two additional baths, which are coupled to the left and
right leads, respectively. The effect of these baths on the leads can be described by using Lindblad operators [1] in the Liouville equation for the density matrix of the dot and the leads. The action of these operators can, in principle, be chosen such that the left and right leads are effectively held in separate thermal equilibrium at different chemical potentials or temperatures, despite the flow of current. An efficient way of solving this Liouville equation is to use the stochastic quantum trajectory method [1]. The intermediate time evolution needed to generate such trajectories can be done with time-dependent NRG (tNRG) based on complete basis sets.
Here we present our preliminary results illustrating the above ideas.
[1] C.W. Gardiner, P. Zoller, Quantum Noise (Springer, Berlin, 2000)