Vibrational wave packet dynamics in the silver tetramer probed by NeNePo femtosecond pump-probe spectroscopy
Institut für Experimentalphysik, Freie Universität Berlin,
D-14195 Berlin, Germany
Corresponding author: a email@example.com
Published online: 15 September 2001
We present results on the ultrafast dynamics of mass-selected neutral Ag4 clusters using NeNePo (negative ion - neutral - positive ion) femtosecond pump-probe spectroscopy. One-color pump-probe spectra of the Ag/Ag4/Ag system measured at 385 nm and an internal cluster temperature of 20 K display a complex beat structure over more than 60 ps. The oscillatory structure is attributed to vibrational wave packet dynamics in an excited "dark" state of neutral Ag4. A dominant 740 fs wave packet period as well as wave packet dephasing and rephasing are observed in the spectra. Fourier analysis of the spectra yields a group of frequencies centered around 45 cm-1 and an anharmonicity of 2.65 cm-1 for the active vibrational mode.
PACS: 36.40.-c – Atomic and molecular clusters / 33.15.Mt – Rotation, vibration, and vibration-rotation constants / 33.80.Eh – Autoionization, photoionization, and photodetachment
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001