Relativistic Effects in LaBi$_2$ Thin Films

TL;DR

This study investigates LaBi$_2$ thin films, revealing their layered growth, metallic nature, and superconductivity, highlighting the role of relativistic effects on their electronic properties and growth behavior.

Contribution

It demonstrates the successful growth of LaBi$_2$ thin films and links their enhanced metallicity and superconductivity to relativistic electronic band structure effects.

Findings

LaBi$_2$ exhibits layer-by-layer growth and superconductivity at ~0.55 K.

Relativistic corrections significantly influence LaBi$_2$'s electronic and surface properties.

LaBi$_2$ shows improved growth dynamics and metallic behavior compared to LaSb$_2$.

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$\textit{Pn}_2$ ($\textit{Pn}$~=~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.