Ferro-octupolar Order and Low-Energy Excitations in d² Double Perovskites of Osmium

Autor(en)

Leonid V. Pourovskii, Dario Fiore Mosca, Cesare Franchini

Abstrakt

Conflicting interpretations of experimental data preclude the understanding of the quantum magnetic state of spin-orbit coupled d2 double perovskites. Whether the ground state is a Janh-Teller-distorted order of quadrupoles or the hitherto elusive octupolar order remains debated. We resolve this uncertainty through direct calculations of all-rank intersite exchange interactions and inelastic neutron scattering cross section for the d2 double perovskite series Ba2MOsO6 (M=Ca, Mg, Zn). Using advanced many-body first-principles methods, we show that the ground state is formed by ferro-ordered octupoles coupled by superexchange interactions within the ground-state Eg doublet. Computed ordering temperature of the single second-order phase transition is consistent with experimentally observed material-dependent trends. Minuscule distortions of the parent cubic structure are shown to qualitatively modify the structure of gaped magnetic excitations.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Institut Polytechnique de Paris, Collège de France, Università di Bologna

Journal

Physical Review Letters

Band

127

Anzahl der Seiten

6

ISSN

0031-9007

DOI

https://doi.org/10.1103/PhysRevLett.127.237201

Publikationsdatum

11-2021

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie, 103018 Materialphysik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/11b136ae-0c27-4138-86be-4d4173b88ad5