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  • Open Access

Mapping the limits of equilibrium in sheared granular liquid crystals

Jacopo Bilotto1,*, Martin Trulsson2, and Jean-François Molinari1

  • *Contact author: jacopo.bilotto@epfl.ch
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Phys. Rev. Research 8, 043151 – Published 10 November, 2026

DOI: https://doi.org/10.1103/cjdt-6d9p

Abstract

While elongated particles in viscous fluids follow Jeffery orbits, their dynamics in dense granular flows remain unresolved. We demonstrate that sheared, low-friction granular rods do not follow these orbits, but instead reach a quasiequilibrium state quantitatively described by classical liquid crystal theory, with collisions providing effective thermal noise. This quasiequilibrium analogy breaks down at two limits: low aspect ratios, where the theory incorrectly predicts isotropy, and high interparticle friction, which drives a transition from steric screening to frictional gearing. We map this far-from-equilibrium breakdown using a phenomenological effective Ericksen number, establishing the limits of thermal thermodynamic analogies in driven athermal matter.

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Phys. Rev. Research 8, 043151– Published 10 November, 2026
  • Received 26 March 2026
  • Accepted 14 October 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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