Interplay of fast and slow dynamics in rare transition pathways: The disk-to-slab transition in the 2d Ising model

Autor(en)

Clemens Moritz, Andreas Troester, Christoph Dellago

Abstrakt

Rare transitions between long-lived stable states are often analyzed in terms of free energy landscapes computed as functions of a few collective variables. Here, using transitions between geometric phases as example, we demonstrate that the effective dynamics of a system along these variables are an essential ingredient in the description of rare events and that the static perspective provided by the free energy alone may be misleading. In particular, we investigate the disk-to-slab transition in the two-dimensional Ising model starting with a calculation of a two-dimensional free energy landscape and the distribution of committor probabilities. While at first sight it appears that the committor is incompatible with the free energy, they can be reconciled with each other using a two-dimensional Smoluchowski equation that combines the free energy landscape with state dependent diffusion coefficients. These results illustrate that dynamical information is not only required to calculate rate constants but that neglecting dynamics may also lead to an inaccurate understanding of the mechanism of a given process.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie, Institut für Lehrer*innenbildung

Externe Organisation(en)

Technische Universität Wien

Journal

Journal of Chemical Physics

Band

147

Anzahl der Seiten

10

ISSN

0021-9606

DOI

https://doi.org/10.1063/1.4997479

Publikationsdatum

10-2017

Peer-reviewed

Ja

ÖFOS 2012

103006 Chemische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie, Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e996d7ca-ee0e-464f-96a1-0da97513829a