Charge transport in mechanically controlled single-molecule break-junctions

We present inelastic electron tunneling spectroscopy (IETS) measurements carried out on single molecules incorporated into a mechanically controllable break-junction (MCBJ) at low temperature. The single molecules contacted with a MCBJ or with a STM show various conductance values under stretching depending on the contact geometry and the molecular conformation ($e.g.$, \textit{trans} or \textit{gauche}). In such single-molecule devices, the metal of electrodes ($e.g.$, gold or platinum) and anchoring groups ($e.g.$, thiol (-SH) or amine (-NH$_{2}))$ can also significantly influence the charge transport through the single molecules. Here we demonstrate how these individual aspects influence the conductance properties of single-molecule junctions.