Simulations of Inelastic Tunnelling in Molecular Bridges

Inelastic Electron Tunneling Spectroscopy of Gold−Benzenedithiol−Gold Junctions: Accurate Determination of Molecular Conformation

“…in 1997, the gold−benzenedithiol−gold (Au−BDT−Au) molecular junction has been the subject of extensive experimental and theoretical investigations, aiming to understand the basic nature of the electron transport in a molecular device. − During many years, the reported experimental conductance values vary by almost 4 orders of magnitude from different research groups and are very difficult to be reproduced by theoretical calculations. One of the major reasons for such problems is the lack of detailed information about the molecular conformation and the contact geometry in actual junctions. − Although the atom-resolved observation of the molecular junction is still out of reach at this stage, the inelastic electron tunneling spectroscopy (IETS) technique can provide experimentally indirect structural information through the response of the molecular vibrations. , In recent years, the IETS technique has been successfully applied to a number of molecular junctions and proved to be a powerful tool to verify the actual presence of the molecule and to extract the geometric information in the molecular junction. − …”

Molecular Origins of Conduction Channels Observed in Shot-Noise Measurements

“…Although this process is only approximate, the interference terms found manifest in our model calculations of conductivity through 1,4-benzenedithiol were 12 orders of magnitude smaller than the primary contributions, making this an excellent practical method for understanding the role of the junction in the process. Indeed, this type of analysis is important for gaining insight into problems such as the operation of inelastic electron tunneling spectroscopy. , Third, the means by which the bridging molecule controls the conductivity can be made manifest by transforming the problem into the basis of molecular-conductance orbitals. This allows for the transmission to be separated into contributions from individual orbitals and the interferences between pairs of orbitals.…”

“…Indeed, this type of analysis is important for gaining insight into problems such as the operation of inelastic electron tunneling spectroscopy. 17,20 Third, the means by which the bridging molecule controls the conductivity can be made manifest by transforming the problem into the basis of molecular-conductance orbitals. This allows for the transmission to be separated into contributions from individual orbitals and the interferences between pairs of orbitals.…”