Berlin 2018 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 71: Poster: Noneq. Stat. Phys., Stoch. Thermo, Brownian Dyn.

DY 71.1: Poster

Donnerstag, 15. März 2018, 15:30–18:00, Poster A

Non-stationary Generalized Langevin Equation for the Crystallization Process — •Philipp Pelagejcev¹, Thomas Voigtmann^3,4, Hugues Meyer^1,2, and Tanja Schilling¹ — ¹Physikalisches Institut, Albert-Ludwigs-Universität, 79104 Freiburg, Germany — ²Research Unit in Engineering Science, Université du Luxembourg, L-4364 Esch-sur-Alzette, Luxembourg — ³Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln, Germany — ⁴Department of Physics, Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany

We study crystallization from an undercooled melt in the context of non-equilibrium statistical physics. We have recently derived an equation of motion for an averaged observable over a bundle of system trajectories by means of time-dependent projection operator techniques. Here we apply this technique to the analysis of simulation trajectories.

We observed the crystallization process of an undercooled fluid of Lennard Jones particles in a Molecular Dynamics Simulation under constant temperature (where the heat bath is realised with a Nosé-Hoover thermostat). From the sampled size of the largest crystalline cluster in the system, we construct the memory kernel of the Generalized Langevin Equation. We observe significant memory effects, i.e. the process is not described well by a Markovian approximation.