Electronic structure of hyper-kagome Na4Ir3O8

We investigate the electronic structure of the frustrated magnet Na4Ir3O8 using density-functional theory. Due to strong spin-orbit coupling, the hyper-kagome lattice is characterized by a half-filled complex of d states, making it a cubic iridium analog of the high-temperature superconducting cuprates. The implications of our results for this unique material are discussed.