Competing magnetic orders and multipolar Weyl fermions in 227 pyrochlore iridates

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Contributors

Abstract

Owing to comparably strong spin-orbit coupling and Hubbard interaction, iridium based 227 pyrochlore oxides harbor a rich confluence of competing magnetic orders and emergent multipolar Weyl quasiparticles. Here we show that this family of materials is predominantly susceptible toward the nucleation of electronic noncoplanar all-in all-out (AIAO) and three-in one-out (3I1O) orders, respectively transforming under the singlet A2u and triplet T1u representations, supporting octupolar and dipolar Weyl fermions, and favored by strong on-site Hubbard and nearest-neighbor ferromagnetic interaction. Furthermore, a coplanar magnetic order generically appears as an intermediate phase between them. This order transforms under the triplet T2u representation and also hosts octupolar Weyl fermions. With the AIAO and 3I1O phases possibly being realized in (Nd1-xPrx)2Ir2O7 when x=0 and 1, respectively, the intervening T2u order can in principle be found at an intermediate doping (0<x<1) or in pressured (hydrostatic) Nd2Ir2O7.

Details

Original languageEnglish
Article numberL241116
JournalPhysical Review B
Volume103
Issue number24
Publication statusPublished - 15 Jun 2021
Peer-reviewedYes