Year: 2026
Type: preprint
Abstract: In non-centrosymmetric bulk materials, electrons flowing in the opposite directions often exhibit different properties. This diode-like effect (i.e., non-reciprocal electron transport) typically originates from relativistic spin-orbit coupling, and its amplitude scales with external magnetic field or magnetization in ferromagnets. Although such rectification is usually absent in antiferromagnets at zero field, recent theories predict that non-coplanar antiferromagnetic order can host large non-reciprocity even without spin-orbit coupling, magnetization or external magnetic fields. This phenomenon - the spontaneous topological diode effect - can potentially be used for efficient electrical readout of antiferromagnetic domains, while it has not been verified for real materials. Here, we report the observation of this effect in a chiral-lattice non-coplanar antiferromagnet CoTa3S6. Nonlinear resistivity measurements reveal the non reciprocal nature of electron transport along the [001] direction at zero field. The observed non-reciprocity exceeds that in typical ferromagnets, whose amplitude is governed by antiferromagnetic order parameter rather than magnetization. First-principles calculations show that the non-coplanar antiferromagnetic order induces asymmetric band dispersions even without spin-orbit coupling, establishing the non-relativistic origin of the observed response. The present findings demonstrate a new mechanism for efficient electrical readout of antiferromagnetic domains, and highlight non-coplanar antiferromagnets as a promising material platform for realizing ferromagnet-like functional responses without relying on spin-orbit coupling or magnetization.
Source: arXiv (Cornell University)
Institutions: Quantum-Phase Electronics Center, School of Engineering, The University of Tokyo, The University of Tokyo, Kyoto University, Hokkaido University, Osaka Metropolitan University, Center for Spintronics Research Network, Osaka University, Toyama Prefectural University, Tokyo Metropolitan University, RIKEN Center for Emergent Matter Science
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1605471664, Material design and electrical manipulation of antiferromagnets with broken time-reversal symmetry, Exploration of novel energy harvesting approach with magnon shift current, Multicaloritronics, Development of order control engineering for antiferromagnetic materials, G3390394593, Magnon propagation control by using magnetic skyrmion crystal, マクロな時間反転対称性の破れた反強磁性体の物質設計と電気的制御, G4388602268, G44962582, G5169585987, 磁気構造探索と統合的物性スクリーニングによる機能反強磁性体設計, Exploration of Novel Material Functions and Physical Phenomena of Skyrmions for Advancement of Skyrmionics, Ferromagnetic Response Induced by Antiferromagnetism: Manifestation of Impurity Contributions and Elucidation of the Underlying Mechanism, Study of electronic states in topological materials by Landau zero-mode observation, G6576490134, G6673561652, Comprehensive exploration of metastable strongly correlated materials as post-spintronics, Improvement and deployment of First-Principles Calculations for Heavy Fermion Systems, G7173229615, 新機構に基づく世界最小のスキルミオンを伴う物質の開拓とダイナミクスの解明, Elucidation of electronic structure and development of physical properties in intercalated transition metal dichalcogenides, Equilibrium skyrmion lattice at zero-magnetic field: Material exploration and magnetoelectric control, G8641032568
OpenAlex ID: W7224117191