Thermally enhanced magnon-phonon resonance in van der Waals antiferromagnet FePS3
Abstract
Strong coupling between collective excitations provides a route to controlling quantum states of matter, yet its evolution under thermal fluctuations remains poorly understood. In the van der Waals antiferromagnet FePS3, strong magnon-phonon coupling is established at low temperatures. At the same time, recent terahertz experiments revealed the counterintuitive stabilization of a long-lived metastable magnetic state with an exceedingly long lifetime of 5 msec at the antiferromagnetic transition, not at the base temperature. This was attributed to a strongly coupled spin-lattice scenario, challenging the conventional wisdom that increased magnetic and thermal fluctuations near TN should be detrimental to the coherent control of a metastable phase. Thus it requires an independent examination for correct understanding. Using high-field Raman spectroscopy, we systematically investigate the temperature evolution of magnon-phonon coupling in FePS3. We observe a pronounced avoided crossing between magnon and phonon modes across a wide range of temperatures and find that the coupling strength remains remarkably robust with increasing temperatures. The zero-field magnon-phonon detuning decreases progressively with warming, driving the system toward resonance and thereby enhancing their hybridization near the transition temperature. This anomalous thermal evolution provides the crucial key to understanding the unusual terahertz-driven states recently reported in FePS3. More broadly, our results highlight van der Waals magnets as a promising platform for strong coupling among collective excitations and for controlling magnetic states through light-matter interactions.
Related
- Coherent terahertz magnon-phonon three-wave mixing in a layered antiferromagnet
- Resonantly Enhanced Phonon Transport by Magnon Pumping in a Ferromagnetic/Piezoelectric Bilayer
- Odd-parity magnon spin polarization from chiral four-spin exchange in a honeycomb antiferromagnet
- Tunable Ultrastrong Magnon-Magnon Coupling and Squeezed States in a Triaxial Van der Waals Antiferromagnet
- Thermodynamic origin of the phonon Hall effect in a honeycomb antiferromagnet
BibTeX
@misc{zhang2026thermally,
title = {{Thermally enhanced magnon-phonon resonance in van der Waals antiferromagnet FePS3}},
author = {Kai-Xuan Zhang and Beom Hyun Kim and Seungbok Lee and Hao Li and Eugene Park and Heejun Yang and Feng Jin and Qingming Zhang and Je-Geun Park},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04229},
eprint = {2611.04229},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04229},
}
RIS
TY - UNPB
TI - Thermally enhanced magnon-phonon resonance in van der Waals antiferromagnet FePS3
AU - Kai-Xuan Zhang
AU - Beom Hyun Kim
AU - Seungbok Lee
AU - Hao Li
AU - Eugene Park
AU - Heejun Yang
AU - Feng Jin
AU - Qingming Zhang
AU - Je-Geun Park
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04229
UR - https://arxiv.org/abs/2611.04229
AB - Strong coupling between collective excitations provides a route to controlling quantum states of matter, yet its evolution under thermal fluctuations remains poorly understood. In the van der Waals antiferromagnet FePS3, strong magnon-phonon coupling is established at low temperatures. At the same time, recent terahertz experiments revealed the counterintuitive stabilization of a long-lived metastable magnetic state with an exceedingly long lifetime of 5 msec at the antiferromagnetic transition, not at the base temperature. This was attributed to a strongly coupled spin-lattice scenario, challenging the conventional wisdom that increased magnetic and thermal fluctuations near TN should be detrimental to the coherent control of a metastable phase. Thus it requires an independent examination for correct understanding. Using high-field Raman spectroscopy, we systematically investigate the temperature evolution of magnon-phonon coupling in FePS3. We observe a pronounced avoided crossing between magnon and phonon modes across a wide range of temperatures and find that the coupling strength remains remarkably robust with increasing temperatures. The zero-field magnon-phonon detuning decreases progressively with warming, driving the system toward resonance and thereby enhancing their hybridization near the transition temperature. This anomalous thermal evolution provides the crucial key to understanding the unusual terahertz-driven states recently reported in FePS3. More broadly, our results highlight van der Waals magnets as a promising platform for strong coupling among collective excitations and for controlling magnetic states through light-matter interactions.
ER -