Lattice symmetry shapes topological spin structures in two-dimensional magnets

May 15, 2026

Lattice symmetry directly shapes topological spin structures in two-dimensional van der Waals magnets, a role typically attributed to interfacial interactions.

(Nanowerk News) Researchers at the Chinese Academy of Sciences have shown that the crystal lattice of a two-dimensional magnet directly shapes topological spin structures in Cr 2Ge2Te6 single crystals. Mapping spin textures whose outlines ranged from triangles to octagons, the team traced the patterns to lattice symmetry and local structural distortions rather than to the interfacial Dzyaloshinskii–Moriya interactions usually credited with producing such textures.

Key Findings

Topological spin structures attract interest for their stability and tunability, and for potential roles in advanced information technologies. They are generally believed to originate from magnetic interactions and external perturbations, but whether the lattice itself can directly shape them in layered van der Waals magnets has remained an open question. The new work addresses that question by combining direct magnetic imaging with simulation and spectroscopy. Prof. LU Qingyou’s group at the High Magnetic Field Laboratory of the Hefei Institutes of Physical Science (HFIPS) led the study, working with Prof. LUO Xuan and SUN Yuping at the HFIPS Institute of Solid State Physics. The findings appeared as a cover article in Advanced Functional Materials (“Lattice‐Driven Topological Spin Textures in Cr2Ge2Te6Single Crystals”). Measurements relied on a low-temperature, high-magnetic-field magnetic force microscope developed in-house at the Steady High Magnetic Field Facility, which allowed the team to image magnetic textures under conditions difficult to reach with conventional microscopy. Cr 2Ge2Te6 was chosen because it combines a layered van der Waals structure with strong magnetocrystalline anisotropy, which locks the preferred magnetization direction to the crystal axes, and strong coupling between adjacent layers. Those properties make it a useful platform for two-dimensional magnetism and spin topology, where the link between crystal geometry and magnetic order can be probed directly. The MFM images revealed clearly defined topological spin structures whose outlines varied from triangular to octagonal. Combining the images with electron spin resonance measurements and micromagnetic simulations, the team found that the shapes tracked lattice symmetry and local structural distortions in the crystal rather than appearing at random positions. The result points to a mechanism in which the lattice sets up competing local energy states that anchor the spin structures in place. That picture differs from the conventional understanding, which attributes similar textures mainly to interfacial Dzyaloshinskii–Moriya interactions, antisymmetric exchange couplings that arise where two materials with different symmetries meet, rather than to the symmetry of a single host crystal. Applied magnetic fields changed the structures in controlled ways, including transitions between different topological states. Some textures behaved like particles, splitting and merging as the field varied. That response shows the spin structures can be tuned by external magnetic fields, adding a second handle, alongside the lattice itself, for controlling their configuration. The findings link crystal symmetry to topological magnetism in a layered material and provide new insight into how magnetic structures arise in low-dimensional systems. They identify the lattice as a direct contributor to spin topology, alongside the magnetic interactions and external perturbations that have dominated previous explanations of these textures.