Real-Time Observation of the Vibration of a Single Adsorbed Molecule

Abstract
The newly developed femtosecond field emission camera was used to observe the time dependence of field emission through a single copper phthalocyanine molecule adsorbed on a tungsten tip. In many of the individual 212-picosecond-long recordings, the field emission was found to oscillate with a frequency between 5 x 10(10) and 20 x 10(10) hertz. The oscillations, which were not observed from a bare tip, are believed to arise from the vibration of a single molecule with respect to the surface. Numerical simulations confirmed the statistical significance of the data.