2015-02-26
10:15 at HCI G 574

Systematic coarse-graining in nucleation theory

Marco Schweizer

Polymer Physics, Department of Materials, ETH Zurich

A vast zoo of models describing the initial stage of nucleation processes has been obtained since Becker and Doering gave the starting signal through their publication about the kinetic theory of nucleation (1935). However, coarse-grained attempts to obtain the key quantity - the nucleation rate - still fail to give accurate results by 3-4 orders of magnitude as compared to brute-force molecular dynamics simulations, considered to be exact. In the talk it is intuitively explained that from a nonequilibrium thermodynamics perspective only one very specific class of nucleation equations can be admissible [1]. We show further evidence in this direction by presenting a connection of microscopic dynamics and the aforementioned coarse-grained structure of admissible equations via a systematic coarse-graining procedure. Finally, we claim that the coarse-graining procedure will not lack 3-4 order of magnitude in nucleation rate predictions. The latter being an artefact of describing nucleation through additional degrees of freedom rather than the amputated choice of a single degree of freedom.