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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 A(2u) and triplet T-1u 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 T-2u representation and also hosts octupolar Weyl fermions. With the AIAO and 3I1O phases possibly being realized in (Nd1-xPrx)(2)Ir2O7 when x = 0 and 1, respectively, the intervening T-2u order can in principle be found at an intermediate doping (0 < x < 1) or in pressured (hydrostatic) Nd2Ir2O7.