Topological insulators and metal-insulator transition in the pyrochlore iridates
Topological insulators and metal-insulator transition in the pyrochlore iridates
The possible existence of topological insulators in cubic pyrochlore iridates ${A}_{2}{\text{Ir}}_{2}{\text{O}}_{7}$ ($A=\text{Y}$ or rare-earth elements) is investigated by taking into account the strong spin-orbit coupling and trigonal crystal-field effect. It is found that the trigonal crystal-field effect, which is always present in real systems, may destabilize the topological insulator proposed …