First Principles Prediction of Topological Phases in Thin Films of Pyrochlore Iridates

TL;DR

This paper predicts topological phases in thin films of pyrochlore iridates using advanced computational methods, revealing potential for oxide electronics applications.

Contribution

It introduces a materials-specific prediction method combining density functional theory and Hartree-Fock for topological phases in iridate thin films.

Findings

Y2Ir2O7 bilayer and trilayer films support topological metallic phases

Direct gap of up to 0.02 eV in these films

Potential for transition metal oxides as topological materials

Abstract

Topological phases have attracted much interest in recent years. While there are a number of three-dimensional materials exhibiting topological properties, there are relatively few two-dimensional examples aside from the well-known quantum Hall systems. Here we make materials-specific predictions for topological phases using density functional theory combined with Hartree-Fock theory that includes the full orbital structure of the relevant iridum $d$-orbitals and the strong but finite spin-orbit coupling strength. We find Y$_2$Ir$_2$O$_7$ bilayer and trilayer films grown along the [111] direction can support topological metallic phases with a direct gap of up to 0.02 eV, which could potentially bring transition metal oxides to the fore as a new class of topological materials with potential applications in oxide electronics.