Семінар Інституту фізики конденсованих систем

Glasses and the glass transition stand, in the much quoted estimate of a Nobel laureate (P.W.Anderson), as "perhaps the deepest and most interesting unsolved problem in condensed matter physics". The talk presents brief review of some known facts about the glass transition, in particular those related to dynamical aspects. In this respect, most of the peculiarities characterizing the glassy state arise in the Thz frequency region, when the wavelength of collective excitations approaches the mean interparticle distance and the disorder plays a role. In the last ten years the advent of Inelastic X-ray Scattering (IXS) allowed to gather an enormous amount of information about those high frequency elementary excitations in glasses and their relation to the crystalline counterpart. This talk includes recent IXS results and discusses open problems of glassy dynamics, which are currently in focus of intensive investigations.