Dynamics in two-dimensional glassy systems of crowded Penrose kites

Abstract

We investigate the translational and rotational relaxation dynamics of a crowded two-dimensional system of monodisperse Penrose kites, in which crystallization, quasi-crystallization and nematic ordering are suppressed, from low to high area fractions along the metastable ergodic fluid branch. First, we demonstrate a decoupling between both the translational and the rotational diffusion coefficients and the relaxation time: the diffusivities are not inversely proportional to the relaxation time, neither in the low-density normal liquid regime nor in the high-density supercooled regime. Our simulations reveal that this inverse proportionality breaks in the normal liquid regime due to the Mermin-Wagner long-wavelength fluctuations and in the supercooled regime due to the dynamical heterogeneities. We then show that dynamical heterogeneities are mainly spatial for translational degrees of freedom and temporal for rotational ones, that there is no correlation between the particles with largest translational and rotational displacements, and that different dynamical length scales characterize the translational and the rotational motion. Hence, despite the translational and the rotational glass-transition densities coincide, according to a mode-coupling fit, translations and rotations appear to decorrelate via different dynamical processes.

Translational and rotational critical-like behaviors in the glass transition of colloidal ellipsoid monolayers

“…Even ellipsoids with a modest p = 2.3 have a higher D than hard spheres with polydispersity up to 16% in 2D ( 19 ); hence, monodisperse ellipsoids are better glass formers than highly polydisperse spheres. The results are consistent with the observation that particle anisotropy can effectively frustrate crystallization, e.g., in monodisperse ellipsoids ( 30 , 58 ), polygon platelets ( 59 ), and spheres with anisotropic interactions ( 20 ). We attribute this to the fact that more anisotropic ellipsoids can pack into more diverse LFSs ( Fig.…”

“…1K ), i.e., corresponding to a more rugged energy landscape. Similarly, binary sphere mixtures ( 18 , 27 ) or polygon platelets ( 59 ) are able to pack into diverse LFSs rather than just polyhedra for polydisperse spheres and hexagon for polydisperse disks, and hence form glasses more easily.…”

Long-wavelength fluctuations and anomalous dynamics in 2-dimensional liquids

“…In the main manuscript, we have presented numerical data for the 2d mKA model and the 2d Harmonic model, and their 3d counterpart for comparison, as well as an experimental data for a 2d suspension of hard ellipses. We note, however, that we have also observed consistent results in a binary system with inverse-power-law potential [26] and in monodisperse systems of Penrose kites [27][28][29] (see SI Appendix, Fig. S5).…”

Softness, anomalous dynamics, and fractal-like energy landscape in model cell tissues

“…To investigate this issue, we focus on the decay of the spatial-temporal correlation function [52,53]:…”