Fermi surface and effective masses of IrO$_2$ probed by de Haas-van Alphen quantum oscillations

TL;DR

This study combines quantum oscillation experiments and band-structure calculations to analyze the Fermi surface and effective masses in IrO$_2$, revealing enhanced effective masses and high sample quality, with implications for its topological properties.

Contribution

It provides detailed experimental and theoretical insights into the Fermi surface and effective masses of IrO$_2$, linking quantum oscillation data with band-structure calculations and recent ARPES findings.

Findings

Effective masses range from 1.9 to 3.0 m_e.

Excellent sample quality indicated by scattering times.

Fermi surface topology matches theoretical predictions.

Abstract

Iridium-containing conducting materials are widely investigated for their strong spin-orbit coupling and potential topological properties. Recently the commonly used electrode material iridium dioxide was found to host a large spin-Hall conductivity and was shown to support Dirac nodal lines. Here we present quantum-oscillation experiments on high-quality IrO$_2$ single crystals using the de Haas-van Alphen effect measured using torque magnetometry with a piezo-resistive microcantilever as well as density functional theory-based band-structure calculations. The angle, temperature and field dependencies of the oscillations and the calculated band dispersion provide valuable information on the properties of the charge carriers, including the Fermi-surface geometry and electronic correlations. Comparison of experimental results to calculations allows us to assigns the observed de Haas-van Alphen frequencies to the calculated Fermi surface topology. We find that the effective masses of IrO$_2$ are enhanced compared to the rest electron mass $m_e$, ranging from 1.9 to 3.0~$m_e$, whereas the scattering times indicate excellent sample quality. We discuss our results in context with recent ARPES and band-structure calculation results that found Dirac nodal lines in IrO$_2$ and compare the effective masses and other electronic properties to those of similar materials like the nodal chain metal ReO$_2$ in which Dirac electrons with very light effective masses have been observed.