Regensburg 2019 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 47: Statistical physics of biological systems II (joint session BP/DY)
DY 47.1: Talk
Thursday, April 4, 2019, 15:00–15:15, H11
Experimental evidence of symmetry breaking of transition-path times — •Jannes Gladrow1, Marco Ribezzi-Crivellari2,3, Felix Ritort3,4, and Ulrich F. Keyser1 — 1Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK — 2Laboratoire de Biochimie (LBC), ESPCI Paris, PSL Research University, CNRS UMR8231 Chimie Biologie Innovation, Paris, France — 3Condensed Matter Physics Department, University of Barcelona, 08028 Barcelona, Spain — 4CIBER-BBN de Bioingenieria, Biomateriales y Nanomedicina, 28029 Madrid, Spain
While thermal rates of state transitions in classical systems have been studied for almost a century, associated transition-path times have only recently received attention. Uphill and downhill transition paths between states at different free energies should be statistically indistinguishable. Here, we systematically investigate transition-path-time symmetry and report evidence of its breakdown on the molecular- and meso-scale out of equilibrium. In automated Brownian dynamics experiments, we establish first-passage-time symmetries of colloids driven by femtoNewton forces in holographically-created optical landscapes confined within microchannels. Conversely, we show that transitions which couple in a path-dependent manner to fluctuating forces exhibit asymmetry. We reproduce this asymmetry in folding transitions of DNA-hairpins driven out of equilibrium and suggest a topological mechanism of symmetry breakdown. Our results are relevant to electrophysiology and single-molecule fluorescence experiments.