Using a hybrid density-functional theory (DFT) calculation including spin-orbit coupling (SOC), we predict that the zigzag antiferromagnetic (AFM) ground state of the honeycomb layered compound Na2IrO3 opens the observed insulating gap through a long-range magnetic order. We show that the effect of SOC and the correction of self-interaction error inherent in previous local or semilocal DFT calculations play crucial roles in predicting the band gap formation in Na2IrO3. It is revealed that the itinerant AFM order with a strong suppression of the Ir magnetic moment is attributed to a considerable hybridization of the Ir 5d orbitals with the O 2p orbitals. Thus, our results suggest that the insulating phase of Na2IrO3 can be represented as a Slater insulator driven by itinerant magnetism.
@article{arxiv.1312.6264,
title = {Antiferromagnetic Slater Insulator Phase of Na2IrO3},
author = {Hyun-Jung Kim and Jun-Ho Lee and Jun-Hyung Cho},
journal= {arXiv preprint arXiv:1312.6264},
year = {2014}
}