Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Tracing Electronic Pathways in Molecules Using Inelastic Tunneling Spectroscopy

Published

Author(s)

Alessandro Troisi, J M. Beebe, Laura B. Picraux, Roger D. van Zee, D R. Stewart, M Ratner, James G. Kushmerick

Abstract

Using inelastic electron tunneling spectroscopy (IETS) to measure the vibronic structure of non-equilibrium molecular transport, aided by a quantitative interpretation scheme based on non-equilibrium Greens function/density functional theory methods, we are able to characterize the actual pathways that the electrons traverse when moving through a molecule in a molecular transport junction. The pathways idea has been present in physical organic chemistry for years in connection with reaction mechanisms, and has been widely used in the interpretation of electron tunneling pathways in proteins, but no distinct observations have been made. We show that the IETS observations directly index electron tunneling pathways along the given normal coordinates of the molecule. One can then interpret the maxima in the IETS spectrum in terms of the specific paths that the electrons follow, as they traverse the molecular junction. IETS measurements therefore not only prove (by the appearance of molecular vibrational frequencies in the spectrum) that the tunneling charges in fact pass through the molecule, but also can be used to determine just what the transport pathways are, and how they change with the geometry and placement of molecules in junctions.
Citation
Proceedings of the National Academy of Sciences of the United States of America
Issue
36

Keywords

molecular electronics, nanotechnology

Citation

Troisi, A. , Beebe, J. , Picraux, L. , van Zee, R. , Stewart, D. , Ratner, M. and Kushmerick, J. (2007), Tracing Electronic Pathways in Molecules Using Inelastic Tunneling Spectroscopy, Proceedings of the National Academy of Sciences of the United States of America (Accessed March 29, 2024)
Created September 3, 2007, Updated October 12, 2021