Collective excitations in metallic glasses: A model of dynamic structure

Abstract
Glasses lack the diffusive nature of dense liquids and the long-range order of crystals, two essential features which, by an elementary argument on the form of the density of collective modes, may be incorporated into a simple model for the displacement-displacement correlation function of a glassy metal. This, in turn, is used to evaluate the dynamic structure factor, and from an application of the theory to a typical system, a dispersion relation for collective excitations is obtained which is found to exhibit a rotonlike minimum.