Ordering and Dynamics of Vibrated Hard Squares

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.

13 pages, 9 pdf figures, 2 tables, to appear in J. Stat. Mech

References in corpus (4)

• Crystallization of a quasi-two-dimensional granular fluid
• Dense Packings of Superdisks and the Role of Symmetry
• Theory and simulation of two-dimensional nematic and tetratic phases
• Enhanced stability of tetratic phase due to clustering

Cited by in corpus (18)

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• Estimating the Critical Parameters of the Hard Square Lattice Gas Model
• Steady states of active Brownian particles interacting with boundaries
• Uniform phases in fluids of hard isosceles triangles: one component and binary mixtures
• Demixing and tetratic ordering in some binary mixtures of hard superellipses
• Role of length-polydispersity on the phase behavior of freely-rotating hard-rectangle fluid
• Dynamics of wet granular hexagons
• Effect of clustering on the orientational properties of a fluid of hard right isosceles triangles
• Hard rectangles near curved hard walls: tuning the sign of the Tolman length
• Universality of the close packing properties and markers of isotropic-to-tetratic crossover in quasi-one-dimensional superdisk fluid
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• The effect of combined roundness and polydispersity on the phase behavior of hard-rectangle fluids
• Exotic liquid crystalline phases in monolayers of vertically vibrated granular particles
• Failure of standard density functional theory to describe the phase behavior of a fluid of hard right isosceles triangles
• Anisotropic skyrmion liquid phase