Title
Antiferro octupolar order in the 5𝑑1 double perovskite Sr2 MgReO6 and its spectroscopic signatures
Abstract
“Hidden”-order phases with high-rank multipolar order parameters have been recently detected in several cubic double perovskites of 5𝑑 transition metals. Here, by constructing and solving an ab initio low-energy Hamiltonian, we show that an antiferroic order of magnetic octupoles also forms in the tetragonal 5𝑑1 double perovskite Sr2 MgReO6. The low-temperature order in this material is determined by a tetragonal crystal field dominating over exchange interactions. This results in a well isolated crystal-field doublet ground state hosting octupolar low-energy degrees of freedom. Very weak dipole moments entangled with the primary octupole order parameters are induced by admixture of the excited 𝑗1/2 spin-orbit multiplet. We show that the octupolar order leads to characteristic quasigapless magnetic excitation spectra, as well as to the intensity of superstructural neutron diffraction reflexes peaking at large scattering momenta.
Keywords
Frustrated magnetismMagnetic interactionsMultipole orderSpin-orbit couplingMott insulatorsDensity functional theoryDynamical mean field theoryMean field theory
Object type
Language
English [eng]
Persistent identifier
Appeared in
Title
Physical Review Research
Volume
7
Issue
3
ISSN
2643-1564
Issued
2025
Publication
American Physical Society (APS)
Version type
Date issued
2025
Access rights
Rights
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