Nonequilibrium Green's functions and their relation to the negative differential conductance in the interacting resonant level model
We evaluate the nonequilibrium 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 nonequ...
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Veröffentlicht in: | Physical review. B 2019-02, Vol.99 (7), p.075139, Article 075139 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | We evaluate the nonequilibrium 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 nonequilibrium 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 nonequilibrium IRLM. The anomalous evolution of the effective 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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ISSN: | 2469-9950 2469-9969 |
DOI: | 10.1103/PhysRevB.99.075139 |