Abstract
alpha -RuCl3 is a major candidate for the realization of the Kitaev quantum spin liquid, but its zigzag antiferromagnetic order at low temperatures indicates deviations from the Kitaev model. We have quantified the spin Hamiltonian of alpha -RuCl3 by a resonant inelastic x-ray scattering study at the Ru L-3 absorption edge. In the paramagnetic state, the quasi-elastic intensity of magnetic excitations has a broad maximum around the zone center without any local maxima at the zigzag magnetic Bragg wavevectors. This finding implies that the zigzag order is fragile and readily destabilized by competing ferromagnetic correlations. The classical ground state of the experimentally determined Hamiltonian is actually ferromagnetic. The zigzag state is stabilized by quantum fluctuations, leaving ferromagnetism - along with the Kitaev spin liquid - as energetically proximate metastable states. The three closely competing states and their collective excitations hold the key to the theoretical understanding of the unusual properties of alpha -RuCl3 in magnetic fields. RuCl3 has stood out as a prime candidate in the search for quantum spin liquids;however, its antiferromagnetic ordering at low temperature suggests deviations from typical QSL models. Here, using resonant inelastic x-ray scattering, the authors provide a comprehensive determination of the low energy effective Hamiltonian.
| Dokumententyp: | Zeitschriftenartikel |
|---|---|
| Fakultät: | Chemie und Pharmazie > Department Chemie |
| Themengebiete: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| ISSN: | 2041-1723 |
| Sprache: | Englisch |
| Dokumenten ID: | 102465 |
| Datum der Veröffentlichung auf Open Access LMU: | 05. Jun. 2023, 15:40 |
| Letzte Änderungen: | 05. Jun. 2023, 15:40 |
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