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arXiv · 1812.08618

Non-equilibrium Green's functions and their relation to the negative differential conductance in the interacting resonant level model

Max E. Sorantin·Wolfgang von der Linden·Roman Lucrezi·Enrico Arrigoni
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Abstract

We evaluate the non-equilibrium single particle Green's functions in the steady state of the interacting resonant level model (IRLM) under the effect of an applied bias voltage. Employing the so-called auxiliary master equation approach, we present accurate nonperturbative results for the non-equilibrium spectral and effective distribution functions, as well as for the current-voltage characteristics. We find a drastic change of these spectral properties between the regimes of low and high bias voltages and discuss the relation of these changes to the negative differential conductance (NDC), a prominent feature in the non-equilibrium IRLM. The anomalous evolution of the distribution function next to the impurity shown by our calculations suggests a mechanism whereby the impurity gets effectively decoupled from the leads at voltages where the NDC sets in, in agreement with previous renormalization group approaches. This scenario is qualitatively confirmed by a Hartree-Fock treatment of the model.

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Max E. Sorantin, Wolfgang von der Linden, Roman Lucrezi, Enrico Arrigoni. 2019-01-23. Non-equilibrium Green's functions and their relation to the negative differential conductance in the interacting resonant level model. https://doi.org/10.1103/physrevb.99.075139

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