Observation of Dirac semi-metallic topological state in SrIrO 3 and CaIrO 3 using terahertz time domain spectroscopy

Experimental realization of quantum phases such as Dirac and Weyl semi metals, topological insulators and superconductors is an emerging subject of interest in condensed matter physics. In this talk, I will give a brief introduction to Dirac semi metals and theoretical predictions of such ground state in orthorhombic perovskite iridates having strong spin orbit coupling. I will present the observation of such 3D Dirac semi metallic ground state in AIrO(3) (A = Ca, Sr) thin films using terahertz time domain spectroscopy.