Epitaxial thin films of pyrochlore iridates: a forward looking approach

TL;DR

This paper reviews the development and potential of epitaxial pyrochlore iridate thin films as a platform for exploring topological phases and unconventional electronic behaviors in strongly correlated, spin-orbit coupled materials.

Contribution

It provides a comprehensive overview of experimental progress in fabricating and studying epitaxial pyrochlore iridate films and discusses future research directions including doping and heterostructure design.

Findings

Evidence of topological phases in epitaxial films

Challenges in producing high-quality films

Potential for designing functional heterostructures

Abstract

Topological quantum materials that show strongly correlated electrons as well as topological order, for which spin-orbit coupling is a key ingredient, exhibit novel states of matter. One such example is the family of pyrochlore iridates, featuring strong spin-orbital coupling, strong electron interactions as well as geometric frustration, making them an ideal platform to study novel topological phases. High-quality epitaxial pyrochlore iridate films, although challenging to produce, provide a pathway to explore unconventional behaviours and unravel the intrinsic properties of these largely unexplored materials. Additionally, designing interfaces with specific properties is crucial to create multilayered devices that can achieve significant technological breakthroughs using topological states of these materials. This article reviews experimental work on epitaxial pyrochlore iridate thin films, discussing evidence of topological phases found in them. Future research directions are outlined, which include exploring the rich tunability offered by chemical doping, especially when combined with the design of epitaxial heterostructures.