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Phase separation kinetics of two-temperature induced phase transition at low density: Cluster growth by ballistic agglomeration

Nayana Venkatareddy1,*, Partha Sarathi Mondal2,*, Shradha Mishra2,†, and Prabal K. Maiti1,‡

  • *These authors contributed equally to this work.
  • †Contact author: smishra.phy@itbhu.ac.in
  • ‡Contact author: maiti@iisc.ac.in
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Phys. Rev. E 114, 035407 – Published 3 September, 2026

DOI: https://doi.org/10.1103/mpmp-23l4

Abstract

We study the kinetics of two-temperature induced phase separation in dilute binary mixtures of active (“hot”) and passive (“cold”) particles using molecular dynamics simulations and a coarse-grained hydrodynamic model. Following a temperature quench, cold particles nucleate into mobile clusters that move ballistically and merge through successive coalescence events. The resulting domain growth exhibits dynamic scaling with a growth exponent ≈0.7, markedly faster than diffusive coarsening. We identify this regime as ballistic agglomeration of cold clusters, demonstrating a distinct nonequilibrium growth mechanism in low-density scalar active systems.

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Phys. Rev. E 114, 035407– Published 3 September, 2026
  • Received 22 December 2025
  • Accepted 22 July 2026
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