title: Nonequilibrium conductance of a  nanodevice for small bias voltage.
abstract: Using nonequilibrium renormalized perturbation theory, we calculate the retarded and lesser self-energies, the spectral density ρ(ω) near the Fermi energy, and the conductance G through a quantum dot as a function of a small bias voltage V, in the general case of electron-hole asymmetry and intermediate valence. The linear terms in ω and V are given exactly in terms of thermodynamic quantities. When the energies necessary to add the first electron (Ed) and the second one (Ed + U) to the quantum dot are not symmetrically placed around the Fermi level, G has a term linear in V if, in addition, either the voltage drop or the coupling to the leads is not symmetric. The effects of temperature are discussed. The results simplify for a symmetric voltage drop, a situation usual in experiment.
authors.affiliation: Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica,8400 Bariloche, Argentina.
authors.forename: A A
authors.initials: AA
authors.lastname: Aligia