Anisotropy in the low energy dynamics of semi metallic CaIr03 thin film

We have investigated the low energy dynamics in CaIrO₃ thin film along two pseudo-cubic in-plane crystal orientations. THz conductivity along two in-plane axes reveals significant difference including semi-metallic characteristics such as low zero frequency conductivity followed by THz absorption peak and high dielectric constants. Carrier localization below room temperature was observed in the Drude-Smith framework of the optical conductivity. No lattice contribution to the optical conductivity was observed, though the lattice symmetries play a crucial role in the electronic structure of perovskite iridates.