seed projects

David Flannigan, Turan Birol, Rafael Fernandes:
Materials for Topological Phononics

Theory-experiment synergy for TP dynamics. (Left) UEM signals interpreted with theory and modeling. (Right) Theory/modeling predictions tested with UEM experiments.

This Seed seeks to significantly advance the understanding and control of topological phonons (TPs) via a combination of ultrafast electron microscopy (UEM), which will directly probe TP dynamics, and theoretical predictions from integrated first-principles calculations and low-energy models. Experimentally, we will demonstrate proof-of-principle scattering geometries that provide direct access to surface TP time-domain dynamics with the highest spatiotemporal resolution of any time-resolved surface-sensitive probe to date. Calculations will be combined with modeling to predict the properties of TPs across different surfaces, their robustness against disorder, their interplay with bulk phonons, and their coupling to surface electronic states. The overall goal is to establish feasibility of these key components in order to nucleate a future Topological Phononics IRG.

Funded by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-2011401