Spin-orbital physics for p orbitals in alkali RO 2 hyperoxides—Generalization of the Goodenough-Kanamori rules
| Autor: | Krzysztof Wohlfeld, Maria Daghofer, Andrzej M. Oles |
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| Rok vydání: | 2011 |
| Předmět: |
Physics
Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics media_common.quotation_subject FOS: Physical sciences General Physics and Astronomy Frustration Alkali metal Condensed Matter - Strongly Correlated Electrons Atomic orbital Superexchange Lattice (order) Antiferromagnetism Condensed Matter::Strongly Correlated Electrons media_common |
| Zdroj: | EPL (Europhysics Letters). 96:27001 |
| ISSN: | 1286-4854 0295-5075 |
| DOI: | 10.1209/0295-5075/96/27001 |
| Popis: | We derive a realistic spin-orbital model at finite Hund's exchange for alkali hyperoxides. We find that, due to the geometric frustration of the oxygen lattice, spin and orbital waves destabilize both spin and p-orbital order in almost all potential ground states. We show that the orbital order induced by the lattice overrules the one favoured by superexchange and that this, together with the large interorbital hopping, leads to generalized Goodenough-Kanamori rules. They (i) lift the geometric frustration of the lattice, and (ii) explain the observed layered C-type antiferromagnetic order in alkali hyperoxides. This is confirmed by a spin-wave dispersion with no soft-mode behavior presented here as a prediction for future experiments. Comment: 7 pages, 5 figures; accepted in EPL |
| Databáze: | OpenAIRE |
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