Effect of deformation on the electronic structure and topological properties of the AIIMg2Bi2 (AII = Mg,Ca,Sr,Ba) compounds

Abstract

The electronic structure and topological properties of the A^IIMg₂Bi₂ (A^II = Mg,Ca,Sr,Ba) compounds are theoretically studied with the use of exact exchange. It is found that the Mg₃Bi₂ compound in the equilibrium state is a semimetal, whereas three other compounds are semiconductors with a direct fundamental band gap. It is predicted that the uniaxial deformation of three-component compounds results in transitions to topologically nontrivial phases: topological insulator and topological and Dirac semimetals. Owing to such a rich variety of topologically nontrivial phases, these compounds may be of interest for further theoretical and experimental studies.