Relativistic Effects in LaBi${}_2$ Thin Films

Abstract

Chemical substitution in crystalline quantum materials is a powerful way to explore the consequences of strong spin-orbit coupling on their structural and electronic properties. In this work, we present an investigation of thin films of the La${\text{Pn}}_2$ ($\text{Pn}$~=~Sb, Bi) class of layered square-net intermetallics. We report the growth of LaBi${}_2$ with a pristine layer-by-layer growth mode, classifying it as a good metal displaying superconductivity at $\sim$0.55~K. Compared to LaSb${}_2$, we attribute the enhanced metallic behavior and improved growth dynamics of LaBi${}_2$ to significant relativistic corrections to its electronic band structure and the resulting impact on both surface energy and intrinsic phonon scattering.