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arXiv · 1510.00656

Ordering and Dynamics of Vibrated Hard Squares

Lee Walsh·Narayanan Menon
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Abstract

We study an experimental system of hard granular squares in two dimensions, energized by vibration. The interplay of order in the orientations and positions of anisotropic particles allows for a rich set of phases. We measure the structure and dynamics of steady states as a function of particle density. This allows us to identify a progression of phases in which a low density isotropic fluid gives way to a phase with tetratic orientational order, short-range translational correlations, and slowed rotational dynamics. In this range of density we also observe a coupling between the molecular orientational order and bond-orientational order. At higher densities, the particles freeze into a translationally and orientationally ordered square crystalline phase in which translational diffusion is suppressed.

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Lee Walsh, Narayanan Menon. 2016-07-07. Ordering and Dynamics of Vibrated Hard Squares. https://doi.org/10.1088/1742-5468%2F2016%2F08%2F083302

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