Theory of elastic and inelastic tunnelling microscopy and spectroscopy: CO on Cu revisited

Based on density functional calculations of an ordered CO structure and a CO dimer on Cu(111), we show that the Tersoff-Hamann approach to tunnelling in a scanning tunnelling microscope (STM) junction and its generalization to vibrational inelastic tunnelling e a useful description of observed STM images and vibrational spectra and microscopy. In particular, this approach provides new physical understanding of vibrational inelastic tunnelling that should not only be useful for the development of single molecule vibrational spectroscopy and microscopy but also of single-bond making and breaking by inelastic electron tunnelling in an STM junction.