Coherent inelastic neutron scattering provides detailed information about the correlated atomic displacements in the vibrational modes of a glass. As an example, we show the wave-vector dependence of the scattering function of vitreous Si${\mathrm{O}}_2$ corresponding to different peaks in the one-phonon density of states. Pending the availability of results from computer simulations, we give a qualitative comparison with the Sen-Thorpe model.

• Received 24 September 1984

DOI:https://doi.org/10.1103/PhysRevLett.54.441