Tunable chiral and nematic states in the triple-Q antiferromagnet CoTaS
arXiv:2507.08148 · doi:10.1038/s41467-026-68843-0
Abstract
Complex spin configurations in magnetic materials, ranging from collinear single-Q to noncoplanar multi-Q states, exhibit rich symmetry and chiral properties. However, their detailed characterization is often hindered by the limited spatial resolution of neutron diffraction techniques. Here we employ magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) to investigate the triangular lattice antiferromagnet CoTaS, revealing three-state (Z3) nematicity and also spin chirality across its multi-Q magnetic phases. At intermediate temperatures, the presence of MLD identifies nematicity arising from a single-Q stripe phase, while at high magnetic fields and low temperatures, a phase characterized solely by MCD emerges, signifying a purely chiral non-coplanar triple-Q state. Notably, at low temperatures and small fields, we discover a unique phase where both chirality and nematicity coexist. A theoretical analysis based on a continuous multi-Q manifold captures the emergence of these distinct magnetic phases, as a result of the interplay between four-spin interactions and weak magnetic anisotropy. Additionally, MCD and MLD microscopy spatially resolves the chiral and nematic domains. Our findings establish CoTaS as a rare platform hosting diverse multi-Q states with distinct combinations of spin chirality and nematicity while demonstrating the effectiveness of polarized optical techniques in characterizing complex magnetic textures.
arXiv comment23 pages total, 5 figures and 9 Supplementary figures
References in corpus (24)
- Skyrmion Lattice in a Chiral Magnet
- Antiferromagnetic spintronics
- Antiferromagnetic spintronics
- Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
- Topological Hall effect in the A-phase of MnSi
- Direct Observation of the Skyrmion Hall Effect
- Anomalous Hall effect arising from noncollinear antiferromagnetism
- Skyrmion lattice with a giant topological Hall effect in a frustrated triangular-lattice magnet
- Multiple-q states and skyrmion lattice of the triangular-lattice Heisenberg antiferromagnet under magnetic fields
- Berry Phase Theory of Anomalous Hall Effect: Application to Colossal Magnetoresistance Manganites
- Topological Hall effect and Berry phase in magnetic nanostructures
- Large magneto-optical Kerr effect and imaging of magnetic octupole domains in an antiferromagnetic metal
- Non-collinear Antiferromagnets and the Anomalous Hall Effect
- Cluster multipole theory for anomalous Hall effect in antiferromagnets
- Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials
- Observation of three-state nematicity in the triangular lattice antiferromagnet Fe NbS
- Discovery of magnetic single- and triple-Q states in Mn/Re(0001)
- Comparing the anomalous Hall effect and the magneto-optical Kerr effect through antiferromagnetic phase transitions in MnSn
- Half-magnetization plateau and the origin of threefold symmetry breaking in an electrically-switchable triangular antiferromagnet
- Composition dependence of bulk properties in the Co-intercalated transition-metal dichalcogenide CoTaS
- Skyrmion Crystals in the Triangular Kondo Lattice Model
- Topological-chiral magnetic interactions in ultrathin films at surfaces
- Wannier states and spin supersolid physics in the triangular antiferromagnet KCo(SeO)
- Machine learning assisted derivation of effective low energy models for metallic magnets