Field-Induced Magnon Decay, Magnon Shadows, and Rotonlike Excitations in the Honeycomb Antiferromagnet YbBr_{3}.
Publisher DOI
PubMed ID
41110089
Abstract
Although the search for quantum many-body phenomena in magnetic materials has a strong focus on highly frustrated systems, even unfrustrated quantum magnets show a multitude of unconventional phenomena in their spin excitation spectra. YbBr_{3} is an excellent realization of the S=1/2 antiferromagnetic Heisenberg model on the honeycomb lattice, and we have performed detailed spectroscopic experiments with both unpolarized and polarized neutrons at all applied magnetic fields up to saturation. We observe extensive excitation continua, which cause strong renormalization and the decay of single magnons at higher fields, while coherent features include field-induced "shadows" of the single magnons and the spectacular emergence of a rotonlike excitation. To guide and interpret our experiments, we performed systematic calculations by the method of cylinder matrix-product states that provide quantitative agreement with the neutron scattering data and a qualitative benchmark for the spectral signatures of strong quantum fluctuations even in the absence of magnetic frustration.
Date Issued
2025-10-03
Publication Type
Article
Language(s)
en
Author(s)
Hernández, J. A. | |
Eberharter, A. A. | |
Schuler, M. | |
Lass, J. | |
Mazzone, D. G. | |
Sibille, R. | |
Raymond, S. | |
Normand, B | |
Roessli, B | |
Läuchli, A M | |
Kenzelmann, M. |
Additional Credits
Journal
Physical Review Letters
Publisher
American Physical Society
ISSN
1079-7114
0031-9007
Access(Rights)
open.access