Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 27: CE: Poster Session
TT 27.57: Poster
Mittwoch, 24. März 2010, 14:00–18:00, Poster D1
Real-time simulations of nonequilibrium transport in the single-impurity Anderson model — •Fabian Heidrich-Meisner1, Adrian Feiguin2, Luis Dias Da Silva3,4, George Martins5, Carlos Bussser5, Enrique Anda6, and Elbio Dagotto3,4 — 1LMU Munich, Germany — 2University of Wyoming, USA — 3ORNL, USA — 4University of Tennessee, USA — 5Oakland University, USA — 6PUC Rio, Brazil
In this work, we consider the single-impurity Anderson model and use the adaptive time-dependent density matrix renormalization group (tDMRG) method to compute real-time currents out of equilibrium [1]. We first focus on the particle-hole symmetric point where Kondo correlations are the strongest and then extend the study of the nonequilibrium transport to the mixed-valence regime. As a main result, we present accurate data for the current-voltage characteristics of this model. As tDMRG is typically implemented with a real-space representation of the noninteracting leads, the Kondo regime, due to the emergent exponentially large Kondo screening length, is difficult to access. We therefore also apply tDMRG to Wilson leads [2], i.e., noninteracting leads with a logarithmic discretization as used in the numerical renormalization group method, and show that in the limit of small biases, perfect conductance can be obtained from tDMRG at much smaller Kondo temperatures than using a real-space representation of the leads.
[1] F. Heidrich-Meisner et al., Phys. Rev B 79, 235336 (2009)
[2] L.G.G.V. Dias da Silva et al., Phys. Rev. B 78 195317 (2008)