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

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.