Grain-boundary scattering between chiral domains in the chiral topological semimetal CoSi
Phys. Rev. B 114, 235411 – Published 20 October, 2026
DOI: https://doi.org/10.1103/l3fc-q8jj
Abstract
We evaluate the electron scattering properties in CoSi thin films having either twin (heterochiral) or nontwin (homochiral) grain boundaries using first-principles quantum transport calculations. We find that scattering across a twin grain boundary is more resistive than scattering across a nontwin grain boundary and that nontwin grain boundaries have a greater percentage of surface conduction than twin grain boundaries. This is corroborated by the transmission eigenstate profiles, which show that the surface Fermi-arc electrons can transmit past the nontwin grain boundaries between homochiral domains on the same surface without significant backscattering. In contrast, these surface electrons get scattered along the twin grain boundaries between heterochiral domains to the opposite surface, resulting in partial forward transmission and partial backscattering that yields higher grain-boundary resistivity. This work helps elucidate the complexities of electron transport in chiral topological semimetals for potential application in next-generation nanointerconnects.