ON THE ORIGIN OF THE LOW-FREQUENCY EXCITATIONS IN GLASSY SELENIUM

The microscopic low-frequency dynamics of glassy selenium is investiga ted by means of the concurrent use of neutron inelastic scattering and computer simulations. A separation of the dynamic response in terms o f intra- and interchain processes is achieved from the analysis of the simulation results. The low-frequency peak in the dynamic structure f actor S(Q, E) as well as the tail of the vibrational density of states Z(E) are then shown to be originated mostly by interchain interaction s. The implications of these findings for the anomalous thermal behavi our of glasses are finally discussed.