Functional renormalization group study of the interacting resonant level model in and out of equilibrium

C. Karrasch, M. Pletyukhov, L. Borda, V. Meden

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

We investigate equilibrium and steady-state nonequilibrium transport properties of a spinless resonant level locally coupled to two conduction bands of width ∼Γ via a Coulomb interaction U and a hybridization t . In order to study the effects of finite bias voltages beyond linear response, a generalization of the functional renormalization group to Keldysh frequency space is employed. Being mostly unexplored in the context of quantum impurity systems out of equilibrium, we benchmark this method against recently published time-dependent density matrix renormalization group data. We thoroughly investigate the scaling limit Γ→∞ characterized by the appearance of power laws. Most importantly, at the particle-hole symmetric point the steady-state current decays like J∼ V-αJ as a function of the bias voltage V≫ t, with an exponent αJ (U) that we calculate to leading order in the Coulomb interaction strength. In contrast, we do not observe a pure power-law (but more complex) current-voltage-relation if the energy ε of the resonant level is pinned close to either one of the chemical potentials ±V/2.

Original languageEnglish
Article number125122
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume81
Issue number12
DOIs
Publication statusPublished - Mar 24 2010

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Bias voltage
Coulomb interactions
Functional groups
Chemical potential
electric potential
Conduction bands
Transport properties
Impurities
conduction bands
Electric potential
transport properties
interactions
exponents
scaling
impurities
decay
energy

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Functional renormalization group study of the interacting resonant level model in and out of equilibrium. / Karrasch, C.; Pletyukhov, M.; Borda, L.; Meden, V.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 81, No. 12, 125122, 24.03.2010.

Research output: Contribution to journalArticle

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