Ferro-octupolar Order and Low-Energy Excitations in d<sup>2</sup> Double Perovskites of Osmium
- Author(s)
- Leonid V. Pourovskii, Dario Fiore Mosca, Cesare Franchini
- Abstract
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(s)
- Computational Materials Physics
- External organisation(s)
- Institut Polytechnique de Paris, Collège de France, University of Bologna
- Journal
- Physical Review Letters
- Volume
- 127
- No. of pages
- 6
- ISSN
- 0031-9007
- DOI
- https://doi.org/10.1103/PhysRevLett.127.237201
- Publication date
- 11-2021
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103015 Condensed matter, 103018 Materials physics
- Keywords
- ASJC Scopus subject areas
- General Physics and Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/11b136ae-0c27-4138-86be-4d4173b88ad5