Molecular transport junctions: Propensity rules for inelastic electron tunneling spectra

Alessandro Troisi, Mark A. Ratner

Research output: Contribution to journalArticle

94 Citations (Scopus)

Abstract

We develop a series of propensity rules for interpreting inelastic electron tunneling (IET) spectra of single-molecule transport junctions. IETS has no selection rules, such as those seen in optical, infrared, and Raman spectra, because IETS features arise not from the field-dipole interaction characterizing these other spectroscopies but from vibronic modification of the electronic levels. Expansion of the Landauer-Imry formula in Taylor series in molecular normal coordinates gives a convenient, accurate perturbation-type formula for calculating both frequency and intensity of the IETS spectrum. Expansion in a Dyson-like form permits derivation of propensity rules, both symmetry-based and pathway-deduced, allowing correlation of structure and coupling geometry with the IETS spectrum. These propensity rules work very well for the calculated spectrum of five typical molecular bridges.

Original languageEnglish
Pages (from-to)1784-1788
Number of pages5
JournalNano letters
Volume6
Issue number8
DOIs
Publication statusPublished - Aug 1 2006

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ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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