The Propagating Nature of Single- and Multimagnons in LaCrO3
Abstract
The dispersion of an excitation is commonly used to infer its microscopic character: dispersive modes are associated with propagation, whereas nondispersive features are often interpreted as localized. This distinction becomes less straightforward for composite excitations, whose spectral maxima can remain nearly dispersionless even when they are built from propagating quasiparticles. Here we use momentum- and temperature-dependent resonant inelastic X-ray scattering (RIXS) to reveal the origin of multimagnon excitations in antiferromagnetic LaCrO3. Whereas the single magnon disperses strongly, the two- and three-magnon features remain nearly flat. On approaching the Neel temperature, thermal population of the magnon band produces an anti-Stokes branch and opens an additional three-magnon channel involving the creation of two magnons and annihilation of one. Its energy and momentum dependence are reproduced by a thermally weighted multimagnon joint density of states calculations. These results establish thermal population as a means of exposing the propagating constituents hidden within nondispersive composite excitations, and position RIXS as a probe of multimagnon dynamics and, ultimately, magnon-magnon interactions.
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BibTeX
@misc{lazemi2026propagating,
title = {{The Propagating Nature of Single- and Multimagnons in LaCrO$_3$}},
author = {Masoud Lazemi and Fabian J. Mohammad and Ellen M. Kiens and Yorick A. Birkhölzer and Paras Mehta and Emma van der Minne and Stefano Agrestini and Frank M. F. de Groot and Hebatalla Elnaggar},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.14792},
eprint = {2609.14792},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.14792},
}
RIS
TY - UNPB
TI - The Propagating Nature of Single- and Multimagnons in LaCrO_3
AU - Masoud Lazemi
AU - Fabian J. Mohammad
AU - Ellen M. Kiens
AU - Yorick A. Birkhölzer
AU - Paras Mehta
AU - Emma van der Minne
AU - Stefano Agrestini
AU - Frank M. F. de Groot
AU - Hebatalla Elnaggar
PY - 2026
DA - 2026/09/13
PB - arXiv
DO - 10.48550/arxiv.2609.14792
UR - https://arxiv.org/abs/2609.14792
AB - The dispersion of an excitation is commonly used to infer its microscopic character: dispersive modes are associated with propagation, whereas nondispersive features are often interpreted as localized. This distinction becomes less straightforward for composite excitations, whose spectral maxima can remain nearly dispersionless even when they are built from propagating quasiparticles. Here we use momentum- and temperature-dependent resonant inelastic X-ray scattering (RIXS) to reveal the origin of multimagnon excitations in antiferromagnetic LaCrO_3. Whereas the single magnon disperses strongly, the two- and three-magnon features remain nearly flat. On approaching the Neel temperature, thermal population of the magnon band produces an anti-Stokes branch and opens an additional three-magnon channel involving the creation of two magnons and annihilation of one. Its energy and momentum dependence are reproduced by a thermally weighted multimagnon joint density of states calculations. These results establish thermal population as a means of exposing the propagating constituents hidden within nondispersive composite excitations, and position RIXS as a probe of multimagnon dynamics and, ultimately, magnon-magnon interactions.
ER -