Combining density functional theory (DFT) and embedded dynamical mean-field theory (DMFT) methods, we study the metal-insulator transition in R2Ir2O7 (R=Y, Eu, Sm, Nd, Pr, and Bi) and the topological nature of the insulating compounds. Accurate free energies evaluated using the charge self-consistent DFT+DMFT method reveal that the metal-insulator transition occurs for an A-cation radius between that of Nd and Pr, in agreement with experiments. The all-in-all-out magnetic phase, which is stable in the Nd compound but not the Pr one, gives rise to a small Ir4+ magnetic moment of ≈0.5μB and opens a sizable correlated gap. We demonstrate that within this state-of-the-art theoretical method, the insulating bulk pyrochlore iridates are topologically trivial.
@article{arxiv.1505.01203,
title = {Metal-insulator transition and topological properties of pyrochlore iridates},
author = {Hongbin Zhang and Kristjan Haule and David Vanderbilt},
journal= {arXiv preprint arXiv:1505.01203},
year = {2017}
}