Stacking-Controlled Altermagnetism and Topological Magnons in Bilayer CrI3
Abstract
Stacked van der Waals magnets provide a tunable route to altermagnetism, a compensated magnetic order characterized by momentum-dependent spin splitting, and to the topological magnetic excitations that such order can host. In bilayer CrI3, first-principles calculations and linear spin-wave theory reveal stacking-controlled altermagnetic order and associated magnon band topology. Combining band-representation analysis with calculations of the dynamic structure factor relevant to inelastic neutron scattering, we further characterize the chirally split topological magnons and quantify their energy corrections and lifetimes using a many-body Green's-function approach. The interlayer magnetic ground state is highly sensitive to the stacking geometry, thereby controlling the magnon band topology and transport responses. We further show that magnon--magnon interactions renormalize the magnon dispersion and dynamic structure factor, with a particular focus on magnon decay. Using van der Waals bilayer CrI3 as a representative platform, our results establish stacking engineering as a structural route for tuning altermagnetism and associated topological magnon excitations, opening avenues toward stacking-controlled spintronic and magnonic devices.
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BibTeX
@misc{xiao2026stackingcontrolled,
title = {{Stacking-Controlled Altermagnetism and Topological Magnons in Bilayer CrI$_3$}},
author = {Lu Xiao and Meng-Han Zhang and Dao-Xin Yao},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.00479},
eprint = {2610.00479},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.00479},
}
RIS
TY - UNPB
TI - Stacking-Controlled Altermagnetism and Topological Magnons in Bilayer CrI_3
AU - Lu Xiao
AU - Meng-Han Zhang
AU - Dao-Xin Yao
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.00479
UR - https://arxiv.org/abs/2610.00479
AB - Stacked van der Waals magnets provide a tunable route to altermagnetism, a compensated magnetic order characterized by momentum-dependent spin splitting, and to the topological magnetic excitations that such order can host. In bilayer CrI_3, first-principles calculations and linear spin-wave theory reveal stacking-controlled altermagnetic order and associated magnon band topology. Combining band-representation analysis with calculations of the dynamic structure factor relevant to inelastic neutron scattering, we further characterize the chirally split topological magnons and quantify their energy corrections and lifetimes using a many-body Green's-function approach. The interlayer magnetic ground state is highly sensitive to the stacking geometry, thereby controlling the magnon band topology and transport responses. We further show that magnon--magnon interactions renormalize the magnon dispersion and dynamic structure factor, with a particular focus on magnon decay. Using van der Waals bilayer CrI_3 as a representative platform, our results establish stacking engineering as a structural route for tuning altermagnetism and associated topological magnon excitations, opening avenues toward stacking-controlled spintronic and magnonic devices.
ER -