Light-induced chiral altermagnets from conventional antiferromagnets
Abstract
Altermagnets combine compensated collinear magnetic order with momentum-dependent nonrelativistic spin splitting, offering new opportunities for spintronic applications. Here, we propose a route to optically induce altermagnetism through coherent lattice control. Using symmetry analysis, we identify phonon distortions that lift the spin degeneracy of conventional antiferromagnets while preserving the rotational symmetries connecting opposite-spin sublattices. Among these, geometric chiral phonons provide a particularly appealing pathway, linking the emergence of altermagnetism to structural chirality. Taking Fe2TeO6 as a prototype, we demonstrate that a linearly polarized mid-infrared pulse can drive a structural instability through negative biquadratic coupling between an infrared-active phonon and an optically silent, symmetry-breaking mode. First-principles-based lattice dynamics reveal the emergence of a transient chiral distortion, while electronic-structure calculations establish that the light-induced structure exhibits nonrelativistic spin splitting characteristic of altermagnetism. Our results establish a symmetry-guided pathway toward the ultrafast optical control of altermagnetic states through nonlinear phononics.
Related
- Magnon Polarization Textures and Transport in Antiferromagnets and Altermagnets
- Piezo-Kerr effect in altermagnets and noncollinear antiferromagnets
- Antiferro-Chiral Phonons as Conjugate Fields to Néel Order in 𝒫𝒯-Symmetric Antiferromagnets
- Chiral-Angle-Controlled Spin Splitting and Spin Transport in Nanotubes Rolled from d-wave Altermagnets
- Exchange-Driven Chiral Magnons and Weyl States in Room-Temperature Metallic XCoB2 (X= Ta, Zr and Hf) Altermagnets
BibTeX
@misc{cardenasgamboa2026lightinduced,
title = {{Light-induced chiral altermagnets from conventional antiferromagnets}},
author = {Jorge Cardenas-Gamboa and Devika Jayadeep and Aritz Leonardo and Gregory A. Fiete and Jeroen van den Brink and Maia G. Vergniory},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.40410},
eprint = {2610.40410},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.40410},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Light-induced chiral altermagnets from conventional antiferromagnets
AU - Jorge Cardenas-Gamboa
AU - Devika Jayadeep
AU - Aritz Leonardo
AU - Gregory A. Fiete
AU - Jeroen van den Brink
AU - Maia G. Vergniory
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.40410
UR - https://arxiv.org/abs/2610.40410
AB - Altermagnets combine compensated collinear magnetic order with momentum-dependent nonrelativistic spin splitting, offering new opportunities for spintronic applications. Here, we propose a route to optically induce altermagnetism through coherent lattice control. Using symmetry analysis, we identify phonon distortions that lift the spin degeneracy of conventional antiferromagnets while preserving the rotational symmetries connecting opposite-spin sublattices. Among these, geometric chiral phonons provide a particularly appealing pathway, linking the emergence of altermagnetism to structural chirality. Taking Fe_2TeO_6 as a prototype, we demonstrate that a linearly polarized mid-infrared pulse can drive a structural instability through negative biquadratic coupling between an infrared-active phonon and an optically silent, symmetry-breaking mode. First-principles-based lattice dynamics reveal the emergence of a transient chiral distortion, while electronic-structure calculations establish that the light-induced structure exhibits nonrelativistic spin splitting characteristic of altermagnetism. Our results establish a symmetry-guided pathway toward the ultrafast optical control of altermagnetic states through nonlinear phononics.
ER -