Abstract
We investigate the bilayer Ruddlesden-Popper iridate SrIrO by temperature-dependent angle-resolved photoemission. At low temperatures, we find a fully gapped correlated insulator, characterized by a small charge gap and narrow bandwidths. The low-energy spectral features show a pronounced temperature-dependent broadening and non-quasiparticle-like Gaussian line shapes. Together, these spectral features provide experimental evidence for a polaronic ground state. We observe similar behavior for the single-layer cousin SrIrO, indicating that strong electron-boson coupling dominates the low-energy excitations of this exotic family of compounds.
- Received 31 January 2013
DOI:https://doi.org/10.1103/PhysRevB.87.241106
©2013 American Physical Society