Eur. Phys. J. B (2013) 86: 319
https://doi.org/10.1140/epjb/e2013-40177-1

Regular Article

Hund and pair-hopping signatures in transport properties of degenerate nanoscale devices

Aix-Marseille Université, CNRS, IM2NP UMR 7334, 13397 Marseille, France

^a e-mail: pierre.lombardo@univ-amu.fr

Received: 4 March 2013
Received in final form: 15 May 2013
Published online: 15 July 2013

Abstract

We investigate the signature of a complete Coulomb interaction in transport properties of double-orbital nanoscale devices. We analyze the specific effects of Hund exchange and pair hopping terms, calculating in particular stability diagrams. It turns out that a crude model, with partial Coulomb interaction, may lead to a misinterpretation of experiments. In addition, it is shown that spectral weight transfers induced by gate and bias voltages strongly influence charge current. The low temperature regime is also investigated, displaying inelastic cotunneling associated with the exchange term, as well as Kondo conductance enhancement.