Title: Evolution of local motifs and topological proximity in self-assembled quasi-crystalline phases
Speaker: Vanessa Robins (Australian National University)
Speaker's URL: https://physics.anu.edu.au/contact/people/profile.php?ID=75
Abstract: With Martin Pedersen, Jacob Kirkensgaard, Kell Mortensen (Copenhagen). Proc. R. Soc. A 476 (2020) http://dx.doi.org/10.1098/rspa.2020.0170
We use the persistent homology of alpha-shape filtrations to analyse the time evolution, convergence, and final state of molecular dynamics simulations of simple point particles. Our analysis reveals the formation and dissipation of specific particle constellations in these trajectories, and shows that the persistence diagrams are sensitive to the nucleation and convergence to a final structure. In particular, we identify the presence of pentagonal bi-pyramid arrangements in icosahedral quasicrystals, and show that their geometry is stabilised by the relative locations of the three local minima in the interaction potential. This identifies the underlying geometric reason for the observation by Engel et al (2015) that a three-well potential is required for quasicrystal formation in single-particle systems.
Additional Dates &/or Times
Tue 11/8 4:10 PM – Pomerene 150 (TGDA seminar slot)
Mon 11/14 12:40 PM – BE 260
Correspondence of max-flow to the absolute permeability of porous systems.
Th 11/17 1:50 PM – BE 130
Tile-Transitive Tilings of the Euclidean and Hyperbolic Planes by Ribbons
URL associated with Seminar: https://tgda.osu.edu/activities/tdga-seminar/