Nonequilibrium Bond Forces in Single-Molecule Junctions

Jonathan Brand, Susanne Leitherer, Nick Rübner Papior, Nicolas Néel*, Yong Lei, Mads Brandbyge, Jörg Kröger

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Passing a current across two touching C60 molecules imposes a nonequilibrium population of bonding and antibonding molecular orbitals, which changes the equilibrium bond character and strength. A current-induced bond force therefore contributes to the total force at chemical-bond distances. The combination of first-principles calculations with scanning probe experiments exploring currents and forces in a wide C60-C60 distance range consistently evidences the presence of current-induced attraction that occurs when the two molecules are on the verge of forming a chemical bond. The unique opportunity to arrange matter at the atomic scale with the atomic force and scanning tunneling microscope tip has enabled closely matching molecular junctions in theory and experiment. The findings consequently represent the first report of current-induced bond forces at the single-molecule level and further elucidate the intimate relation between charge transport and force. The results are relevant to molecular electronics and chemical reactions in the presence of a current.
Original languageEnglish
JournalNano Letters
Volume19
Issue number11
Pages (from-to)7845-7851
Number of pages7
ISSN1530-6984
DOIs
Publication statusPublished - 2019

Keywords

  • Density functional theory
  • Nonequilibrium Green's function
  • Atomic force microscopy
  • Scanning tunelling microscopy
  • Single-module junction
  • C60

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