Absence of Dirac states in BaZnBi$_{2}$ induced by spin-orbit coupling

TL;DR

This study investigates BaZnBi₂'s magnetotransport properties, revealing that spin-orbit coupling removes Dirac states from the Fermi level, affecting electronic transport and highlighting the influence of atomic mass and magnetic order.

Contribution

It demonstrates that spin-orbit coupling gaps out Dirac states in BaZnBi₂, contrasting with related materials, and emphasizes the role of atomic mass and magnetic order in Dirac state presence.

Findings

Dirac states are absent at the Fermi level due to SOC.

Electronic transport dominated by small hole and electron pockets.

SOC-induced gap in Dirac states is larger than in SrMnBi₂.

Abstract

We report magnetotransport properties of 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 three dimensional (3D) but also with quasi two dimensional (2D) portions of the Fermi surface. The spin-orbit coupling-induced gap in Dirac states is much larger when compared to isostructural SrMnBi$_{2}$. This suggests that not only long range magnetic order but also mass of the alkaline earth atoms A in ABX$_{2}$ (A = alkaine 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