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arXiv · 1611.07997

Electron interactions, spin-orbit coupling, intersite correlations in pyrochlore iridates

Runzhi Wang·Ara Go·Andrew J. Millis
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Abstract

We perform combined density functional and dynamical mean-field calculations to study the pyrochlore iridates Lu$_2$Ir$_2$O$_7$, Y$_2$Ir$_2$O$_7$ and Eu$_2$Ir$_2$O$_7$. Both single-site and cluster dynamical mean-field calculations are performed and spin-orbit coupling is included. Paramagnetic metallic phases, antiferromagnetic metallic phases with tilted Weyl cones and antiferromagnetic insulating phases are found. The magnetic phases display all-in/all-out magnetic ordering, consistent with previous studies. Unusually for electronically three dimensional materials, the single-site dynamical mean-field approximation fails to reproduce qualitative material trends, predicting in particular that the paramagnetic phase properties of Y$_2$Ir$_2$O$_7$ and Eu$_2$Ir$_2$O$_7$ are almost identical, although in experiments the Y compound has a much higher resistance than the Eu compound. This qualitative failure is attributed to the importance of intersite magnetic correlations in the physics of these materials.

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Runzhi Wang, Ara Go, Andrew J. Millis. 2016-11-23. Electron interactions, spin-orbit coupling, intersite correlations in pyrochlore iridates. https://doi.org/10.1103/physrevb.95.045133

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