Cody Schimming - Interplay of Geometry and Topology in Nematic Materials
Please note this event occurred in the past.
March 05, 2026 11:30 am - 12:30 pm ET
LGRT 1033. Refreshments at 11:15
Interplay of Geometry and Topology in Nematic Materials
Abstract: Interplays between geometry and topology are ubiquitous in physical systems. Constraints imposed by topology often lead to complex energy landscapes and elaborate dynamics. Materials with local orientational order, called nematics, exemplify these interplays. In this talk, I will discuss two clear examples of leveraging such interplays to characterize and control nematics.
In the first part of the talk, I will show how well-known two-dimensional topological measures may be generalized to much more complicated three-dimensional nematic line defects. This generalization yields a surprising amount of information about the local geometry of the defects and can be used to characterize defects from nematic data. I will then show how topological conservation laws lead to theoretical predictions about the motion of defects, and compare these predictions with experiments on line defect annihilation.
In the second part of the talk I will discuss computational work on two-dimensional active nematics. These are nematic materials where the constituents exert microscopic forces that translate to macroscopic flows. I will show that embedding topological constraints into the system using inclusions can dramatically alter its dynamics, allowing predictable and tunable phases including unidirectional flows and both ferromagnetic and antiferromagnetic vortex lattices.
Biosketch: Dr. Schimming earned his PhD in Physics at the Univ. of Minnesota in 2022 with a thesis entitled, "Theoretical and Computational Methods for Mesoscopic Textures in Nematic Liquid Crystals with Anisotropic Elasticity," with Jorge Vinals. He then had a 2-year postdoctoral fellowship at Los Alamos National Lab, working with Charles and Cynthia Reichhardt on geometric confinement effects in active nematic liquid crystals. In 2024, he moved to Johns Hopkins Univ., where he is the William H. Miller III Postdoctoral Fellow, working with Daniel Beller and Brian Camley on topology and geometry, dynamics, non-equilibrium phase transitions, and motion of cellular tissues. Here is his Google Scholar page.