Article abstract


Nature Materials 7, 870 - 877 (2008)
Published online: 12 October 2008 | doi:10.1038/nmat2293

Subject Categories: Glasses | Colloids | Computation, modelling and theory

Universal link between the boson peak and transverse phonons in glass

Hiroshi Shintani1 & Hajime Tanaka1


The physical properties of a topologically disordered amorphous material (glass), such as heat capacity and thermal conductivity, are markedly different from those of its ordered crystalline counterpart. The understanding of these phenomena is a notoriously complex problem. One of the universal features of disordered glasses is the 'boson peak', which is observed in neutron and Raman scattering experiments. The boson peak is typically ascribed to an excess density of vibrational states. Here, we study the nature of the boson peak, using numerical simulations of several glass-forming systems. We discovered evidence suggestive of the equality of the boson peak frequency to the Ioffe–Regel limit for 'transverse' phonons, above which transverse phonons no longer propagate. Our results indicate a possibility that the origin of the boson peak is transverse vibrational modes associated with defective soft structures in the disordered state. Furthermore, we suggest a possible link between slow structural relaxation and fast boson peak dynamics in glass-forming systems.

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  1. Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan

Correspondence to: Hajime Tanaka1 e-mail: tanaka@iis.u-tokyo.ac.jp



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