Interaction of quasilocal harmonic modes and boson peak in glasses - art. no. 132203

The direct, proportionality relation between the boson peak maximum in glas ses omega (b) and the Ioffe-Regel crossover frequency for phonons omega (d) is established. For several investigated materials omega (b) = (1.5 +/- 0. 1)omega (d). At frequency omega (d) the mean free path of the phonons l bec omes equal to their wavelength because of strong resonant scattering on qua silocal harmonic oscillators. We prove that the established correlation bet ween omega (b) and omega (d) holds in the general case and is a direct cons equence of bilinear coupling of quasilocal oscillators with the strain fiel d.