R. Yamamoto - Academia.edu (original) (raw)
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Papers by R. Yamamoto
Physical Review Letters, 1998
The diffusivity of tagged particles is demonstrated to be very heterogeneous on time scales compa... more The diffusivity of tagged particles is demonstrated to be very heterogeneous on time scales comparable to or shorter than the α relaxation time τα ( ∼ = the stress relaxation time) in a highly supercooled liquid via 3D molecular dynamics simulation. The particle motions in the relatively active regions dominantly contribute to the mean square displacement, giving rise to a diffusion constant systematically larger than the Einstein-Stokes value. The van Hove self-correlation function Gs(r, t) is shown to have a long distance tail which can be scaled in terms of r/t 1/2 for t < ∼ 3τα. Its presence indicates heterogeneous diffusion in the active regions. However, the diffusion process eventually becomes homogeneous on time scales longer than the life time of the heterogeneity structure (∼ 3τα).
Physical Review Letters, 1998
The diffusivity of tagged particles is demonstrated to be very heterogeneous on time scales compa... more The diffusivity of tagged particles is demonstrated to be very heterogeneous on time scales comparable to or shorter than the α relaxation time τα ( ∼ = the stress relaxation time) in a highly supercooled liquid via 3D molecular dynamics simulation. The particle motions in the relatively active regions dominantly contribute to the mean square displacement, giving rise to a diffusion constant systematically larger than the Einstein-Stokes value. The van Hove self-correlation function Gs(r, t) is shown to have a long distance tail which can be scaled in terms of r/t 1/2 for t < ∼ 3τα. Its presence indicates heterogeneous diffusion in the active regions. However, the diffusion process eventually becomes homogeneous on time scales longer than the life time of the heterogeneity structure (∼ 3τα).