Calculation of Vibrational Lifetime of Single Adsorbate on Metal Surfaces with STM

The vibrational lifetimes of single adsorbate on metal surfaces with STM are calculated using nonequilibrium Keldysh Green s function method. The vibrational lifetime is important parameter of the vibrational heating mechanism. This time is inverse of the vibrational decay rate i.e. the passing electron should spend enough time in the adsorbate environment in order to be able to excite it. And in order to estimate the change in conductance in an inelastic electron tunneling spectroscopy (IETS) experiments, we need to know the vibrational lifetimes to excite the adsorbate vibration. Depending on our calculations, we conclude that the resonant width, the vibrational frequency of the adsorbate, the strength of electron-vibration coupling, all are important parameters to determine the physical features for the processes concerned the nanostructures which are adsorbed on the metal surfaces.