Generalization and applicability of the Landauer formula for nonequilibrium current in the presence of interactions

H. Ness, L. K. Dash, and R. W. Godby
Phys. Rev. B 82, 085426 – Published 17 August 2010

Abstract

Using nonequilibrium Green’s functions (NEGFs), we calculate the current through an interacting region connected to noninteracting leads. The problem is reformulated in such a way that a Landauer-like term appears in the current as well as extra terms corresponding to nonequilibrium many-body effects. The interaction in the central region renormalizes not only the Green’s functions but also the coupling at the contacts between the central region and the leads, allowing the total current to be further expressed as a generalized Landauer-like current formula. The general expression for the dynamical functional that renormalizes the contacts is provided. We analyze in detail under what circumstances Landauer-like approaches to the current, i.e., without contact renormalization, are valid for interacting electron-electron and/or electron-phonon systems. Numerical NEGF calculations are then performed for a model electron-phonon coupled system in order to validate our analytical approach. We show that the conductance for the off-resonant transport regime is adequately described by Landauer-like approach in the small-bias limit while for the resonant regime, the Landauer-like approach results depart from the exact results even at small finite bias. The validity of applying a Landauer-like approach to inelastic electron-tunneling spectroscopy is also studied in detail.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 7 April 2010

DOI:https://doi.org/10.1103/PhysRevB.82.085426

©2010 American Physical Society

Authors & Affiliations

H. Ness*, L. K. Dash, and R. W. Godby

  • Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom and European Theoretical Spectroscopy Facility (ETSF)

  • *hn506@york.ac.uk

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 82, Iss. 8 — 15 August 2010

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×