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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 6: Active Matter 1 (joint session BP/CPP/DY)
CPP 6.5: Vortrag
Montag, 5. September 2022, 12:00–12:15, H16
Premelting controlled active matter in ice — •Jeremy Vachier1 and John S. Wettlaufer1,2 — 1Nordita, KTH Royal Institute of Technology and Stockholm University, Hannes Alfvéns väg 12, SE-106 91 Stockholm, Sweden — 2Yale University, New Haven, Connecticut 06520-8109, USA
Self-propelled particles can undergo complex dynamics due to a range of bulk and surface interactions. In the case of a foreign particle inside a subfreezing solid, such as a particle in ice, a premelted film can form around it allowing the particle to migrate under the influence of an external temperature gradient, which is a phenomenon called thermal regelation. It has recently been shown that the migration of particles of a biological origin can accelerate melting in a column of ice and thereby migrate faster. We have previously shown that the effect of regelation plays a major role in the migration of inert particles and impurities inside ice, with important environmental implications. In particular, the question of how the activity affects a particle's position over time is essential for paleoclimate dating methods in ice cores. We re-cast this class of regelation phenomena in the stochastic framework of active Ornstein-Uhlenbeck dynamics and make predictions relevant to this and related problems of interest in geophysical and biological problems.