Tunable Semimetallic State in Compressive-strained SrIrO3 Films Revealed by Transport Behaviors

TL;DR

This study demonstrates how compressive strain in SrIrO3 films can induce a tunable semimetallic state, revealing strain-dependent electronic properties and potential for novel quantum states.

Contribution

It provides detailed analysis of strain-induced electronic structure changes in SrIrO3 films, showing how substrate-induced strain can tune their semimetallic behavior.

Findings

Strain alters Hall effect and resistance behavior in SrIrO3 films.

Band structure shifts under strain lead to semimetallic state tuning.

Strain-induced semimetallic transition suggests potential for topological states.

Abstract

Orthorhombic SrIrO3 is a typical spin-orbit-coupling correlated metal that shows diversified physical properties under the external stimuli. Here nonlinear Hall effect and weakly temperature-dependent resistance are observed in a SrIrO3 film epitaxially grown on SrTiO3 substrate. It infers that orthorhombic SrIrO3 is a semimetal oxide. However, linear Hall effect and insensitive-temperature-dependent resistance are observed in SrIrO3 films grown on (La,Sr)(Al,Ta)O3 (LSAT) substrates, suggesting a tunable semimetallic state due to band structure change in SrIrO3 films under different compressive strain. The mechanism of this evolution is explored in detail through strain-state analysis by reciprocal space mapping and electron diffraction, carrier density and mobility calculations, as well as electronic band structure evolution under compressive strain (predicted by tight-binding approximation). It might suggest that the strain-induced band shift leads to the semimetallic tuning in the SrIrO3 film grown on from SrTiO3 to LSAT substrates. Our findings illustrate the tunability of SrIrO3 properties and pave the way to induce novel physical states in SrIrO3 such as the proposed topological insulator state in heterostructures.