Electron-phonon interactions in topologically protected conducting channel of atomically thin Bi (111)

Two-dimensional topological insulators possess a single conducting channel embedded inside the insulating bulk surface bandgap, which can be complicated to realize in practical devices due to electron-phonon interactions (EPI) at finite temperatures. Using single bilayer Bi (111) (SBB) and the first-principles method, we show that the EPI strongly depend on the edge states dispersion. Particularly, when the dispersion of the topological edge electronic states becomes more linear, the EPI gets negligibly weaker and vice versa. In addition, we find that the surface phonons have nonzero topological invariant, suggesting the existence of topological phononic edge states in SBB.

About the presenter

Enamul Haque is a PhD Student at Monash University with CI Nikhil Medhekar. His research specialises in the areas of advanced functional materials sciences within the field of computational materials science, as part of FLEET’s Research Theme 1, Topological Materials.