Details

Autor(en) / Beteiligte

• Solon, Alexandre P
• Chaté, Hugues
• Tailleur, Julien

Titel

From phase to microphase separation in flocking models: the essential role of nonequilibrium fluctuations

Ist Teil von

• Physical review letters, 2015-02, Vol.114 (6), p.068101-068101, Article 068101

Ort / Verlag

United States: American Physical Society

Erscheinungsjahr

2015

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• We show that the flocking transition in the Vicsek model is best understood as a liquid-gas transition, rather than an order-disorder one. The full phase separation observed in flocking models with Z(2) rotational symmetry is, however, replaced by a microphase separation leading to a smectic arrangement of traveling ordered bands. Remarkably, continuous deterministic descriptions do not account for this difference, which is only recovered at the fluctuating hydrodynamics level. Scalar and vectorial order parameters indeed produce different types of number fluctuations, which we show to be essential in selecting the inhomogeneous patterns. This highlights an unexpected role of fluctuations in the selection of flock shapes.