Nearly-Logarithmic Decay of Correlations in Glass-forming Liquids
Prof. Wolfgang Götze (TU München)

Recent measurements of some response function by optical Kerr-effect spectroscopy are used to explain the discovery of nearly -logarithmic relaxation in some standard glass-forming liquids. Then,the universal relaxation laws as predicted by the mode-coupling theory (MCT) for the evolution of glassy dynamics are briefly reviewed and the concept of a description of data by schematic MCT models is explained. The scenario of nearly-logarithmic decay of correlations is identified as a generic but not universal implication of the critical decay law near the MCT glass-transition singularity. It is demonstrated that a schematic MCT-model can describe relaxation data for a time interval extending over more than five orders of magnitude.It is shown within the fully microscopic version of the MCT, that the phenomenon of nearly-logarithmic decay should occur also for the simple hard-spere system and, indeed, that it has been measured - but not explicitely noticed - in light-scattering experiments of the mean-squared displacement in hard-sphere colloidal suspensions.