Insights into electron-phonon interactions in transition metal oxides
Researchers from the Max Planck Institute for Solid State Research in Stuttgart have measured the complex dielectric function of Na3Ir3O8 single crystals by spectroscopic ellipsometry in the far-infrared at ANKA-IR1. The experiments provide insights into electron-phonon interactions in transition metal oxides.
The complex dielectric function of high-quality Na3Ir3O8 single crystals determined by spectroscopic ellipsometry in the spectral range from 15 meV to 2 eV is reported.
The far-infrared phonon spectra exhibit highly asymmetric line shapes characteristic of Fano resonances. With decreasing temperature, a sharp increase of the infrared intensity of the Fano-shaped phonon modes was observed accompanied by concomitant changes in the low-energy electronic background, formed by electronic transitions between Ir 5d t2g bands of a mostly Jeff = 1/2 character. The role of the complex hyperkagome lattice structure and strong spin-orbit coupling is considered.
D. Pröpper, A. N. Yaresko, T. I. Larkin, T. N. Stanislavchuk, A. A. Sirenko, T. Takayama, A. Matsumoto, H. Takagi, B. Keimer, and A. V. Boris: Fano Resonances in the Infrared Spectra of Phonons in Hyperkagome Na3Ir3O8, Phys. Rev. Lett. 112, 087401 – Published 26 February 2014