Double occupancy and magnetic susceptibility of the Anderson impurity model out of equilibrium

Dirks, Andreas; Schmitt, S.; Han, J. E.; Anders, F.; Werner, Philipp; Pruschke, Thomas

doi:10.1209/0295-5075/102/37011

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Journal article

Double occupancy and magnetic susceptibility of the Anderson impurity model out of equilibrium

Dirks, Andreas Institut für Theoretische Physik, Universität Göttingen, Germany - Department of Physics, State University of New York at Buffalo, USA - Department of Physics, Georgetown University - Washington, USA
Schmitt, S. Lehrstuhl für Theoretische Physik II, Technische Universität Dortmund, Germany - Honda Research Institute Europe GmbH, Offenbach, Germany
Han, J. E. Department of Physics, State University of New York at Buffalo, USA
Anders, F. Lehrstuhl für Theoretische Physik II, Technische Universität Dortmund, Germany
Werner, Philipp Department of Physics, University of Fribourg, Switzerland
Pruschke, Thomas Institut für Theoretische Physik, Universität Göttingen, Germany

01.05.2013

Published in:

EPL (Europhysics Letters). - 2013, vol. 102, no. 3, p. 37011

English We use different numerical approaches to calculate the double occupancy and magnetic susceptibility as a function of a bias voltage in an Anderson impurity model. Specifically, we compare results from the Matsubara voltage quantum Monte Carlo approach (MV-QMC), the scattering states numerical renormalization group (SNRG), and real-time quantum Monte Carlo (RT-QMC), covering Coulomb repulsions ranging from the weak-coupling well into the strong-coupling regime. We observe a distinctly different behavior of the double occupancy and the magnetic response. The former measures charge fluctuations and thus only indirectly exhibits the Kondo scale, while the latter exhibits structures on the scale of the equilibrium Kondo temperature. The Matsubara voltage approach and the scattering states numerical renormalization group yield consistent values for the magnetic susceptibility in the Kondo limit. On the other hand, all three numerical methods produce different results for the behavior of charge fluctuations in strongly interacting dots out of equilibrium.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

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