Effective bias and potentials in steady-state quantum transport: A NEGF reverse-engineering study

Research output: Contribution to journalArticle

Abstract

Using non-equilibrium Green's functions combined with many-body perturbation theory, we have calculated steady-state densities and currents through short interacting chains subject to a finite electric bias. By using a steady-state reverse-engineering procedure, the effective potential and bias which reproduce such densities and currents in a non-interacting system have been determined. The role of the effective bias is characterised with the aid of the so-called exchange-correlation bias, recently introduced in a steady-state density-functional- theory formulation for partitioned systems. We find that the effective bias (or, equivalently, the exchange-correlation bias) depends strongly on the interaction strength and the length of the central (chain) region. Moreover, it is rather sensitive to the level of many-body approximation used. Our study shows the importance of the effective/exchange-correlation bias out of equilibrium, thereby offering hints on how to improve the description of density- functional-theory based approaches to quantum transport.

Details

Authors
Organisations
External organisations
  • University of Jyväskylä
  • European Theoretical Spectroscopy Facility (ETSF)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics
Original languageEnglish
Article number012018
JournalJournal of Physics: Conference Series
Volume696
Issue number1
Publication statusPublished - 2016 Apr 12
Publication categoryResearch
Peer-reviewedYes