Nonlinear Spin Polarization Enables Néel Order Switching in Centrosymmetric Altermagnets
Abstract
Deterministic electrical switching of the Néel order remains challenging in centrosymmetric altermagnets, where linear current-induced spin polarization is forbidden by inversion symmetry. Here, we establish a nonlinear route to Néel order control. Spin group symmetry shows that, in the nonrelativistic limit, the nonlinear spin polarization is constrained along the Néel vector, with a staggered response allowed in $8$ of the $10$ nontrivial spin-Laue groups. Although this Néel spin polarization is torque-inactive by itself, finite spin-orbit coupling can generate an additional uniform component transverse to the Néel vector. Using a minimal model for the d-wave altermagnet FeSb2, we demonstrate the coexistence of the nonrelativistic staggered response with an SOC-induced uniform transverse component. Landau-Lifshitz-Gilbert equation-based macro-spin simulations reveal that the transverse component alone produces oscillatory dynamics, whereas its cooperative action with the staggered response enables deterministic 180∘ reversal. We further show that changing the electric field orientation reverses the staggered spin response and selects the switching direction, while the opposite Néel states can be distinguished by their anomalous Hall response. Our results establish a nonlinear electrical write-read scheme for centrosymmetric altermagnets.
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BibTeX
@misc{das2026nonlinear,
title = {{Nonlinear Spin Polarization Enables Néel Order Switching in Centrosymmetric Altermagnets}},
author = {Sunit Das and Sayan Sarkar and Amit Agarwal},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.26709},
eprint = {2609.26709},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.26709},
}
RIS
TY - UNPB
TI - Nonlinear Spin Polarization Enables Néel Order Switching in Centrosymmetric Altermagnets
AU - Sunit Das
AU - Sayan Sarkar
AU - Amit Agarwal
PY - 2026
DA - 2026/09/22
PB - arXiv
DO - 10.48550/arxiv.2609.26709
UR - https://arxiv.org/abs/2609.26709
AB - Deterministic electrical switching of the Néel order remains challenging in centrosymmetric altermagnets, where linear current-induced spin polarization is forbidden by inversion symmetry. Here, we establish a nonlinear route to Néel order control. Spin group symmetry shows that, in the nonrelativistic limit, the nonlinear spin polarization is constrained along the Néel vector, with a staggered response allowed in $8$ of the $10$ nontrivial spin-Laue groups. Although this Néel spin polarization is torque-inactive by itself, finite spin-orbit coupling can generate an additional uniform component transverse to the Néel vector. Using a minimal model for the d-wave altermagnet FeSb_2, we demonstrate the coexistence of the nonrelativistic staggered response with an SOC-induced uniform transverse component. Landau-Lifshitz-Gilbert equation-based macro-spin simulations reveal that the transverse component alone produces oscillatory dynamics, whereas its cooperative action with the staggered response enables deterministic 180^∘ reversal. We further show that changing the electric field orientation reverses the staggered spin response and selects the switching direction, while the opposite Néel states can be distinguished by their anomalous Hall response. Our results establish a nonlinear electrical write-read scheme for centrosymmetric altermagnets.
ER -