# Anisotropic spatially heterogeneous dynamics in a model glass-forming binary mixture

@article{Flenner2006AnisotropicSH, title={Anisotropic spatially heterogeneous dynamics in a model glass-forming binary mixture}, author={Elijah Flenner and Grzegorz Szamel}, journal={Journal of Physics: Condensed Matter}, year={2006}, volume={19}, pages={205125} }

We calculated a four-point correlation function G4(k, r; t) and the corresponding structure factor S 4 (K, ; t) for a model glass-forming binary mixture. These functions measure the spatial correlations of the relaxation of different particles. We found that these four-point functions are anisotropic and depend on the angle between vectors k and r (or q). The anisotropy is the strongest for times somewhat longer than the β relaxation time, but it is quite pronounced even for times comparable to… Expand

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#### References

SHOWING 1-10 OF 24 REFERENCES

Spatially heterogeneous dynamics investigated via a time-dependent four-point density correlation function

- Chemistry
- 2003

Relaxation in supercooled liquids above their glass transition and below the onset temperature of “slow” dynamics involves the correlated motion of neighboring particles. This correlated motion… Expand

Time-dependent, four-point density correlation function description of dynamical heterogeneity and decoupling in supercooled liquids

- Chemistry
- 2000

by neighboring particles. We evaluate these quantities for a cold Lennard-Jones ~LJ! liquid, and show that in this system x 4(t) is dominated by growing spatial correlations between localized… Expand

Spatial correlations of mobility and immobility in a glass-forming Lennard-Jones liquid.

- Physics, Medicine
- Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
- 1999

Using extensive molecular dynamics simulations of an equilibrium, glass-forming Lennard-Jones mixture, it is shown that spatial correlations exist among particles undergoing extremely large ("mobile") or extremely small ("immobile") displacements over a suitably chosen time interval. Expand

Cooperativity and spatial correlations near the glass transition: computer simulation results for hard spheres and disks.

- Physics, Medicine
- Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
- 2000

A simple way of quantification in terms of the strength and the length scale of dynamic correlations among different particles is demonstrated, and it is shown that for appropriately chosen X(i)(t) the authors obtain finite cooperativity in the limit t-->infinity. Expand

Relaxation in a glassy binary mixture: comparison of the mode-coupling theory to a Brownian dynamics simulation.

- Mathematics, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2005

The wave-vector-dependent relaxation time is shown to be qualitatively different from the predictions of the mode-coupling theory for temperatures where hopping-like motion is present, and there are substantial differences for the non-Gaussian parameter. Expand

Dynamical susceptibility of glass formers: contrasting the predictions of theoretical scenarios.

- Physics, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2005

The four-point correlation function that characterizes nontrivial cooperative dynamics in glassy systems within several models of glasses is computed, finding that the exponent mu is rather small, mu<1 , with a value in reasonable agreement with the MCT predictions, but not with the prediction of simple diffusive defect models, KCM's with noncooperative defects, and CRR's. Expand

Growing correlation length on cooling below the onset of caging in a simulated glass-forming liquid.

- Physics, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2002

A calculation of a fourth-order, time-dependent density correlation function that measures higher-order spatiotemporal correlations of the density of a liquid finds that the characteristic length scale provides a measure of the spatially heterogeneous nature of the dynamics of the liquid in the alpha-relaxation regime. Expand

Spatially correlated dynamics in a simulated glass-forming polymer melt: analysis of clustering phenomena.

- Materials Science, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2001

It is shown that the characteristic time of the maximum cluster size follows the scaling predicted by mode-coupling theory (MCT) for the beta time scale, revealing a possible connection between spatially heterogeneous dynamics and MCT. Expand

Relaxation in a glassy binary mixture: mode-coupling-like power laws, dynamic heterogeneity, and a new non-Gaussian parameter.

- Physics, Medicine
- Physical review. E, Statistical, nonlinear, and soft matter physics
- 2005

A new non-Gaussian parameter is defined whose maximum occurs approximately at the time at which the two peaks in the probability distribution of the logarithm of displacements are most evident, approaching the commonly reported mode-coupling temperature. Expand

Dynamical heterogeneity close to the jamming transition in a sheared granular material.

- Materials Science, Medicine
- Physical review letters
- 2005

The dynamics of a bidimensional dense granular packing under cyclic shear is experimentally investigated and reveals that the grain relaxations are strongly correlated and spatially heterogeneous, especially at the time scale of the collective rearrangements. Expand