Using first-principles calculations, we study the electronic structure of an unexplored Zintl compound, KCdBi. Our calculations establish KCdBi to be a rare example of a strong Z₂ topological semimetal. The compound is found to be cleavable with a small cleavage energy (0. 20. 16em{0ex}J/m^2). The nanostructured KCdBi obtained by cleaving turned out to be a topological insulator, causing a semimetal to insulator transition upon dimensionality reduction. A rich phase diagram emerges upon application of an electric field to nanostructured KCdBi, which consists of topological insulating, Z₂ topological metallic, weak and strong Rashba phases. This compound thus offers a platform to study nontrivial properties tunable by electric field and dimensionality. Our findings are expected to stimulate experimental investigation of this interesting compound.
Ghosh et al. (Tue,) studied this question.