Condensed Matter Physics, 2008, vol. 11, No. 1(53), p. 127, English

Title: Collective dynamics of simple liquids: A mode-coupling description
  W.Schirmacher (Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA; Physik-Department E13, Technische Universität München, James-Franck-Strasse 1, D-85747 Garching, Germany ) ,
  H.Sinn (Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA; Hasylab/DESY, Notkestrasse 85, D-22607 Hamburg, Germany) ,

We use the mode-coupling theory (MCT), which has been highly successful in accounting for the anomalous relaxation behaviour near the liquid-to-glass transition, for describing the dynamics of simple (i.e. monatomic) liquids away from the glass formation regime. We find that the dynamical structure factor predicted by MCT compares well to experimental findings and results of computer simulations. The memory function exhibits a two-step decay as found frequently in experimental and simulation data. The long-time relaxation regime, in which the relaxation rate strongly depends on the density and is identified as the α relaxation. At high density this process leads the glass instability. The short-time relaxation rate is fairly independent of density.

Key words: liquid dynamics, collective excitations in liquids, simple liquids, mode-coupling theory
PACS: 62.60.+V, 66.20.-d

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