The electronic structure of the high-symmetry perovskite iridate Ba2IrO4

Abstract

We report angle-resolved photoemission (ARPES) measurements, density functional and model tight-binding calculations on Ba _2 IrO _4 (Ba-214), an antiferromagnetic ( T _N = 230 K) insulator. Ba-214 does not exhibit the rotational distortion of the IrO _6 octahedra that is present in its sister compound Sr _2 IrO _4 (Sr-214), and is therefore an attractive reference material to study the electronic structure of layered iridates. We find that the band structures of Ba-214 and Sr-214 are qualitatively similar, hinting at the predominant role of the spin–orbit interaction in these materials. Temperature-dependent ARPES data show that the energy gap persists well above T _N , and favor a Mott over a Slater scenario for this compound.