Quantum interference in off-resonant transport through single molecules

Research output: Contribution to journalArticle

Abstract

We provide a simple set of rules for predicting interference effects in off-resonant transport through single molecule junctions. These effects fall into two classes, showing, respectively, an odd or an even number of nodes in the linear conductance within a given molecular charge state, and we demonstrate how to decide the interference class directly from the contacting geometry. For neutral alternant hydrocarbons, we employ the Coulson-Rushbrooke-McLachlan pairing theorem to show that the interference class is decided simply by tunneling on and off the molecule from same or different sublattices. More generally, we investigate a range of smaller molecules by means of exact diagonalization combined with a perturbative treatment of the molecule-lead tunnel coupling. While these results generally agree well with GW calculations, they are shown to be at odds with simpler mean-field treatments. For molecules with spin-degenerate ground states, we show that for most junctions interference causes no transmission nodes, but we argue that it may lead to a nonstandard gate dependence of the zero-bias Kondo resonance.

Details

Authors
  • Kim G. L. Pedersen
  • Mikkel Strange
  • Martin Leijnse
  • Per Hedegard
  • Gemma C. Solomon
  • Jens Paaske
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Condensed Matter Physics
Original languageEnglish
Article number125413
JournalPhysical Review B (Condensed Matter and Materials Physics)
Volume90
Issue number12
Publication statusPublished - 2014
Publication categoryResearch
Peer-reviewedYes