Abstract
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.
3 More- Received 20 December 2018
- Revised 6 February 2019
DOI:https://doi.org/10.1103/PhysRevB.99.075139
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