Photostimulated desorption of Xe from Au(001) surfaces via transient Xe-   formation
  Photo-stimulated desorption (PSD) of Xe atoms from the Au(001) surface in thermal and nonthermal regimes was investigated by the time-of-flight measurement at photon energies of 6.4 and 2.3 eV. Xe was desorbed in a thermal way at high laser fluence, which was in good agreement with theoretical simulations. At a low laser fluence, on the other hand, desorption was induced only at a photon energy of 6.4 eV by a non-thermal one-photon process. We argue that the nonthermal PSD occurs via transient formation of Xe- on Au(001). The lifetime of Xe- is estimated to be ~15 fs with a classical model calculation. Whereas the electron affinity of Xe is negative in the isolated state, it is stabilized by the metal proximity effect. 
Akihiko Ikeda, Masuaki Matsumoto, Shohei Ogura, Katsuyuki Fukutani and   Tatsuo Okano
cond-mat.mes-hall physics.atom-ph physics.chem-ph