Faculté des sciences

Phase diagram of pyrochlore iridates: all-in\char21{}All-out magnetic ordering and non-Fermi-liquid properties

Shinaoka, Hiroshi ; Hoshino, Shintaro ; Troyer, Matthias ; Werner, Philipp

In: Physical Review Letters, 2015, vol. 115, no. 15, p. 156401

We study the prototype 5d pyrochlore iridate Y2Ir2O7 from first principles using the local density approximation and dynamical mean-field theory (LDA+DMFT). We map out the phase diagram in the space of temperature, on-site Coulomb repulsion U, and filling. Consistent with experiments, we find that an all-in–all-out ordered insulating phase is stable for realistic values of U. The trigonal... More

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    Summary
    We study the prototype 5d pyrochlore iridate Y2Ir2O7 from first principles using the local density approximation and dynamical mean-field theory (LDA+DMFT). We map out the phase diagram in the space of temperature, on-site Coulomb repulsion U, and filling. Consistent with experiments, we find that an all-in–all-out ordered insulating phase is stable for realistic values of U. The trigonal crystal field enhances the hybridization between the jeff=1/2 and jeff=3/2 states, and strong interband correlations are induced by the Coulomb interaction, which indicates that a three-band description is important. We demonstrate a substantial band narrowing in the paramagnetic metallic phase and non-Fermi-liquid behavior in the electron- or hole-doped system originating from long-lived quasi-spin-moments induced by nearly flat bands.