Magnetic field effects on spin-split band and magnon transport in altermagnets and emergent compensated ferrimagnets
Abstract
In altermagnets and fully compensated ferrimagnets, not only the electron band but also the magnon band exhibits spin splitting without net magnetization, which enables thermal activation of the magnon spin current. Here, we theoretically investigate magnetic field effects on the magnon properties of these antiferromagnets in the presence of a weak easy-axis anisotropy which makes the collinear states robust against the magnetic field. For the altermagnet and compensated ferrimagnet, we analyze a 2 sublattice order in the J1-J2-J2′ model on the square lattice and a triple-bf Q 12-sublattice order in the J1-J3 model on the kagome lattice, respectively, each accompanied by d-wave and s-wave spin splitting at zero field. It is shown that for positive (negative) magnetic field H whose energy scale is smaller than the anisotropy gap, the up- and down-spin magnon bands are shifted to lower (higher) and higher (lower) energies, respectively, similarly to the Zeeman coupling in electron systems. In the altermagnet, with increasing field, the d-wave splitting tends to be deformed into the s-wave one, which is reflected as the change in the direction of the spin current generated by thermal gradient. In the compensated ferrimagnet, the s-wave nature, i.e., the population imbalance between the up- and down-spin magnons at H=0, can induce an asymmetric field dependence of the longitudinal spin and thermal conductivities in a field-sweep process.
Versions
Related
- Finite-Temperature Magnetism and Longitudinal Spin Transport in Compensated Half-Metal Ferrimagnets with Near-Zero Magnetization
- Emergent magnetic nonanalyticity in Dirac altermagnets
- Robust skyrmion nucleation and transport via composition gradient in rare earth-transition metal ferrimagnets
- Emergent Skyrmion Hall Effect in d-wave Altermagnets at Finite Temperature
- A Compensated Mini-Permeameter for Localized Magnetic Loss Measurements on Magnetic Laminations
BibTeX
@misc{aoyama2026magnetic,
title = {{Magnetic field effects on spin-split band and magnon transport in altermagnets and emergent compensated ferrimagnets}},
author = {Kazushi Aoyama and Hikaru Kawamura},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.03451},
eprint = {2606.03451},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.03451},
}
RIS
TY - UNPB
TI - Magnetic field effects on spin-split band and magnon transport in altermagnets and emergent compensated ferrimagnets
AU - Kazushi Aoyama
AU - Hikaru Kawamura
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2606.03451
UR - https://arxiv.org/abs/2606.03451
AB - In altermagnets and fully compensated ferrimagnets, not only the electron band but also the magnon band exhibits spin splitting without net magnetization, which enables thermal activation of the magnon spin current. Here, we theoretically investigate magnetic field effects on the magnon properties of these antiferromagnets in the presence of a weak easy-axis anisotropy which makes the collinear states robust against the magnetic field. For the altermagnet and compensated ferrimagnet, we analyze a 2 sublattice order in the J_1-J_2-J_2^′ model on the square lattice and a triple-bf Q 12-sublattice order in the J_1-J_3 model on the kagome lattice, respectively, each accompanied by d-wave and s-wave spin splitting at zero field. It is shown that for positive (negative) magnetic field H whose energy scale is smaller than the anisotropy gap, the up- and down-spin magnon bands are shifted to lower (higher) and higher (lower) energies, respectively, similarly to the Zeeman coupling in electron systems. In the altermagnet, with increasing field, the d-wave splitting tends to be deformed into the s-wave one, which is reflected as the change in the direction of the spin current generated by thermal gradient. In the compensated ferrimagnet, the s-wave nature, i.e., the population imbalance between the up- and down-spin magnons at H=0, can induce an asymmetric field dependence of the longitudinal spin and thermal conductivities in a field-sweep process.
ER -