Experimental Evidence for Three Universality Classes for Reaction Fronts in Disordered Flows.

Phys Rev Lett

CNRS-Laboratoire de Physique Théorique de l'Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.

Published: June 2015

Self-sustained reaction fronts in a disordered medium subject to an external flow display self-affine roughening, pinning, and depinning transitions. We measure spatial and temporal fluctuations of the front in 1+1 dimensions, controlled by a single parameter, the mean flow velocity. Three distinct universality classes are observed, consistent with the Kardar-Parisi-Zhang (KPZ) class for fast advancing or receding fronts, the quenched KPZ class (positive-qKPZ) when the mean flow approximately cancels the reaction rate, and the negative-qKPZ class for slowly receding fronts. Both qKPZ classes exhibit distinct depinning transitions, in agreement with the theory.

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http://dx.doi.org/10.1103/PhysRevLett.114.234502DOI Listing

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