Project Details
Projekt
Large-Scale Monte-Carlo Simulations of Biopolymer Systems using Event-Chain Algorithms
Applicant
Dr. Tobias Alexander Kampmann
Subject Area
Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
Experimental and Theoretical Physics of Polymers
Experimental and Theoretical Physics of Polymers
Term
from 2018 to 2022
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 398458812
The general aim of this project is to generalize the event-chain MC algorithm for various applications in polymer systems, e.g. cytoskeletal filament systems, in order to develop a new and efficient method for this important class of systems. Besides the simulation of semiflexible polymers, polymers consisting of infinitely thin needles or polymer systems with explicit crosslinkers or branching agents (like ARP 2/3) and even triangulated, elastic surfaces / capsules can be simulated in a general, universal event chain framework. We expect a significant increase in efficiency. It is an ongoing effort to improve the sampling efficiency, on this topic we will cooperate with Prof. Krauth and Dr. Michel.As a precursor to the simulation of polymer networks, we will investigate the generation of (nearly) equilibrated, homogeneous and isotropical (semiflexible) polymer melts as initial configurations. The optional swap move and the advantage of ECa in dense systems should make it possible to study the solidification of such melts.The main system we propose to investigate are polymer networks in equilibrium, where the attractive interaction is mediated by a generic homogeneous square well potential or by the explicit simulation of (transient) crosslinkers or branching agents. Here, we focus on the self-assembly of bundle networks and propose to extensively study the emerging foam-like structures in two dimensions. The planned collaboration with Dr. Schnauß will allow a thorough comparison of our numerics to (minimal) in-vitro systems. Contrary to two-dimensional polymer networks, where the emerging structure has foam-like properties (driven by free energy minimization), the situation becomes more complex in three dimensions. The network will minimize the total bundle length, but a foam will reduce the total area, which is not well defined in the polymer network system.As to the second part, we want to focus on two- or three-dimensional colloidal systems containing dense hard needles or sphero-cylinders as an model for a liquid crystal. The transition from an isotropic to a (quasi-)nematic phase in two dimensions is presumably of Kosterlitz-Thouless type, where the (quasi-)nematic phase exhibits only quasi-long-range order. In D=3, additional colloids in a liquid crystal host system produce topological defects by introducing additional boundary conditions, which induce an effective interaction between colloids. This may lead to a tetravalent chemistry of colloids, which implies the possibility of (controlled) self-assembly.
DFG Programme
Research Grants
International Connection
France
