Sloutskin, EliEliSloutskinHuber, PatrickPatrickHuberWolff, MatthiasMatthiasWolffOcko, Benjamin M.Benjamin M.OckoMadsen, AndersAndersMadsenSprung, MichaelMichaelSprungSchön, VolkerVolkerSchönBaumert, JulianJulianBaumertDeutsch, MosheMosheDeutsch2022-07-052022-07-052008-06-03Physical Review E 77 (6): 060601 (2008)http://hdl.handle.net/11420/13005The dynamics of thermal capillary waves (CWs) on an ionic liquid's surface are studied at the transition from propagating to overdamped CWs by x-ray photon correlation spectroscopy. The analysis considers both homodyne and heterodyne contributions, and yields excellent full line-shape experiment-theory agreement for the structure factor. The CWs' Brillouin scattering becomes extinct at a critical temperature Tc JK ∼10 K above Tc LL, the propagating modes' hydrodynamic limit, in agreement with linear response theory. Surprisingly, the same power law applies at both Tc. The results rule out the presence of a suggested surface dipole layer.en1550-237620086American Physical SocietyPhysikJournal Article10.1103/PhysRevE.77.060601Other