# Functional renormalization group study of the interacting resonant level model in and out of equilibrium - Condensed Matter > Strongly Correlated Electrons

Functional renormalization group study of the interacting resonant level model in and out of equilibrium - Condensed Matter > Strongly Correlated Electrons - Download this document for free, or read online. Document in PDF available to download.

Abstract: We investigate equilibrium and steady-state non-equilibrium transportproperties of a spinless resonant level locally coupled to two conduction bandsof width ~\Gamma via a Coulomb interaction U and a hybridization t-. In orderto study the effects of finite bias voltages beyond linear response, ageneralization of the functional renormalization group to Keldysh frequencyspace is employed. Being mostly unexplored in the context of quantum impuritysystems out of equilibrium, we benchmark this method against recently-publishedtime-dependent density matrix renormalization group data. We thoroughlyinvestigate the scaling limit \Gamma\to\infty characterized by the appearanceof power laws. Most importantly, at the particle-hole symmetric point thesteady-state current decays like J ~ V^{-\alpha J} as a function of the biasvoltage V>>t-, with an exponent \alpha JU that we calculate to leading orderin the Coulomb interaction strength. In contrast, we do not observe a purepower-law but more complex current-voltage-relation if the energy \epsilon ofthe resonant level is pinned close to either one of the chemical potentials \pmV-2.

Author: ** C. Karrasch, M. Pletyukhov, L. Borda, V. Meden**

Source: https://arxiv.org/