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arXiv · 2506.10333

Nonlinear N\'eel Spin-Orbit Torque in Centrosymmetric Antiferromagnets

Jin Cao·Weikang Wu·Huiying Liu·Shen Lai·Cong Xiao·X. C. Xie·Shengyuan A. Yang
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Abstract

Electric control of N\'eel vector is a central task of antiferromagnetic (AFM) spintronics. The major scheme so far relies on the linear N\'eel torque, which however is restricted to AFMs with broken inversion symmetry. Here, we propose a nonlinear N\'eel spin-orbit torque, uniquely enabling electric control in the vast class of centrosymmetric AFMs, where the existing scheme fails. Importantly, its intrinsic component, rooted in sublattice-resolved band quantum geometry, offers two additional advantages: It operates also in $\mathcal{PT}$-symmetric AFM insulators, where linear torque is forbidden; and it has anti-damping character, making it more efficient in driving magnetic dynamics. Combined with first-principles calculations, we predict large effect in MnRh and MnBi$_{2}$Te$_{4}$, which can be readily detected in experiment. Our work unveils a new fundamental effect, offers a new strategy of electric control in AFM systems beyond the existing paradigm, and opens the door to the field of nonlinear AFM spintronics.

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Jin Cao, Weikang Wu, Huiying Liu, Shen Lai, Cong Xiao, X. C. Xie, Shengyuan A. Yang. 2025-06-12. Nonlinear N\'eel Spin-Orbit Torque in Centrosymmetric Antiferromagnets. https://arxiv.org/abs/2506.10333

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