LMP Seminar: Nonreciprocal collective dynamics in a mixture of phoretic Janus colloids

LMP Seminar

  • Datum: 23.04.2024
  • Uhrzeit: 14:00 - 15:30
  • Vortragende(r): Dr. Gennaro Tucci
  • Dept. of Living Matter Physics, MPI for Dynamics and Self-Organization
  • Ort: Max-Planck-Institut für Dynamik und Selbstorganisation (MPIDS)
  • Raum: Riemannraum 1.40 & ZOOM Meeting ID: 997 1155 2453 Passcode: 771001
  • Gastgeber: MPIDS / LMP
  • Kontakt: golestanian-office@ds.mpg.de
A multicomponent mixture of Janus colloids with distinct catalytic coats and phoretic mobilities is a promising theoretical system to explore the collective behavior arising from nonreciprocal interactions. An active colloid produces (or consumes) chemicals, self-propels, drifts along chemical gradients, and rotates its intrinsic polarity to align with a gradient. As a result the connection from microscopics to continuum theories through coarse-graining couples densities and polarization fields in unique ways. Focusing on a binary mixture, we show that these couplings render the unpatterned reference state unstable to small perturbations through a variety of instabilities including oscillatory ones which arise on crossing an exceptional point or through a Hopf bifurcation. For fast relaxation of the polar fields, they can be eliminated in favor of the density fields to obtain a microscopic realization of the Nonreciprocal Cahn-Hilliard model for two conserved species with two distinct sources of non-reciprocity, one in the interaction coefficient and the other in the interfacial tension. Our work establishes Janus colloids as a versatile model for a bottom-up approach to both scalar and polar active mixtures.
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