Interplay of Spin-Orbit Interactions, Dimensionality, and Octahedral Rotations in Semimetallic SrIrO$_3$

TL;DR

This study synthesizes SrIrO3 and uses in situ photoemission to reveal its narrow-band semimetallic electronic structure, highlighting the effects of spin-orbit coupling, dimensionality, and octahedral rotations.

Contribution

It demonstrates the synthesis and electronic characterization of SrIrO3, showing how structural factors influence its semimetallic behavior and challenge existing models.

Findings

Discovery of narrow bands from spin-orbit and structural effects

Breakdown of single-band Mott insulator picture in SrIrO3

Structural control influences electronic properties

Abstract

We employ reactive molecular-beam epitaxy to synthesize the metastable perovskite SrIrO$_{3}$ and utilize {\it in situ} angle-resolved photoemission to reveal its electronic structure as an exotic narrow-band semimetal. We discover remarkably narrow bands which originate from a confluence of strong spin-orbit interactions, dimensionality, and both in- and out-of-plane IrO$_6$ octahedral rotations. The partial occupation of numerous bands with strongly mixed orbital characters signals the breakdown of the single-band Mott picture that characterizes its insulating two-dimensional counterpart, Sr$_{2}$IrO$_{4}$, illustrating the power of structure-property relations for manipulating the subtle balance between spin-orbit interactions and electron-electron interactions.