Tsai, C.-S.C.-S.TsaiLin, C.-E.C.-E.LinLin, J.-C.J.-C.LinWang, J.-K.J.-K.Wang2020-06-022020-06-02199800092614https://scholars.lib.ntu.edu.tw/handle/123456789/496507Surface Raman scattering was performed on Si(100)-2×1:H. The analysis of the temperature-dependent spectral profiles of the SiH stretch with the Persson-Rydberg dephasing model has led to an exchange mode (ω0) at 647±79 cm-1, a coupling parameter (δω) equal to -30±8 cm-1, and a friction parameter (η0) equal to 59±3 cm-1. The extrapolated pure dephasing time at 100 K, however, was found to be inconsistent with the direct time-resolved measurement [P. Guyot-Sionnest, P.H. Lin, E.M. Hiller, J. Chem. Phys. 102 (1995) 4269]. This controversy can be resolved by proposing another exchange mode at ~200 cm-1, coexisting with the one at ~650 cm-1. This multi-mode dephasing model generalizes the existing single-mode model.journal article10.1016/S0009-2614(98)00990-7