Absence of Dirac states in BaZnBi2 induced by spin-orbit coupling

Abstract

We report magnetotransport properties of ${\mathrm{BaZnBi}}_{2}$ single crystals. Whereas electronic structure features Dirac states, such states are removed from the Fermi level by spin-orbit coupling (SOC) and consequently electronic transport is dominated by the small hole and electron pockets. Our results are consistent with not only three-dimensional, but also with quasi-two-dimensional portions of the Fermi surface. The SOC-induced gap in Dirac states is much larger when compared to isostructural ${\mathrm{SrMnBi}}_{2}$. This suggests that not only long-range magnetic order, but also mass of the alkaline-earth atoms $A$ in ${ABX}_{2}\phantom{\rule{4pt}{0ex}}(A=$ alkaline-earth, $B=$ transition-metal, and $X=$ Bi/Sb) are important for the presence of low-energy states obeying the relativistic Dirac equation at the Fermi surface.