229 research outputs found
The crystallization of asymmetric patchy models for globular proteins in solution
Asymmetric patchy particle models have recently been shown to describe the
crystallization of small globular proteins with near quantitative accuracy.
Here, we investigate how asymmetry in patch geometry and bond energy generally
impact the phase diagram and nucleation dynamics of this family of soft matter
models. We find the role of the geometry asymmetry to be weak, but the energy
asymmetry to markedly interfere with the crystallization thermodynamics and
kinetics. These results provide a rationale for the success and occasional
failure of George and Wilson's proposal for protein crystallization conditions
as well as physical guidance for developing more effective protein
crystallization strategies.Comment: 10 pages, 8 figure
Decorrelation of the static and dynamic length scales in hard-sphere glass-formers
We show that in the equilibrium phase of glass-forming hard-sphere fluids in
three dimensions, the static length scales tentatively associated with the
dynamical slowdown and the dynamical length characterizing spatial
heterogeneities in the dynamics unambiguously decorrelate. The former grow at a
much slower rate than the latter when density increases. This observation is
valid for the dynamical range that is accessible to computer simulations, which
roughly corresponds to that of colloidal experiments. We also find that in this
same range, no one-to-one correspondence between relaxation time and
point-to-set correlation length exists. These results point to the coexistence
of several relaxation mechanisms in the accessible dynamical regime of
three-dimensional hard-sphere glass formers.Comment: 8 pages, 7 figure
Dimensional study of the dynamical arrest in a random Lorentz gas
The random Lorentz gas is a minimal model for transport in heterogeneous
media. Upon increasing the obstacle density, it exhibits a growing subdiffusive
transport regime and then a dynamical arrest. Here, we study the dimensional
dependence of the dynamical arrest, which can be mapped onto the void
percolation transition for Poisson-distributed point obstacles. We numerically
determine the arrest in dimensions d=2-6. Comparing the results with standard
mode-coupling theory reveals that the dynamical theory prediction grows
increasingly worse with . In an effort to clarify the origin of this
discrepancy, we relate the dynamical arrest in the RLG to the dynamic glass
transition of the infinite-range Mari-Kurchan model glass former. Through a
mixed static and dynamical analysis, we then extract an improved dimensional
scaling form as well as a geometrical upper bound for the arrest. The results
suggest that understanding the asymptotic behavior of the random Lorentz gas
may be key to surmounting fundamental difficulties with the mode-coupling
theory of glasses.Comment: 9 pages, 6 figure
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