Twist-controlled magnetism grows beyond the moiré

Writing in Nature Nanotechnology, researchers now show that magnetism, too, can defy conventional expectations: in twisted antiferromagnetic layers, spin order need not be confined to the moiré unit cell, but can expand into unexpectedly large, topological textures that span hundreds of nanometres.

Most moiré phenomena inherit their defining length scale directly from the interference pattern between lattices. Magnetic order in stacked van der Waals magnets has therefore been assumed to follow the same rule. The new work overturns this assumption. Studying twisted double-bilayer chromium triiodide (CrI₃) with scanning nitrogen–vacancy magnetometry, the authors directly image magnetic fields with nanoscale resolution and observe long-range textures extending well beyond a single moiré cell, up to ~300 nm, an order of magnitude larger than the underlying wavelength.

The behaviour is counterintuitive. As the twist angle decreases, the moiré wavelength grows, yet the observed magnetic texture size evolves in the opposite direction, peaking near 1.1° before vanishing above ~2°.

This inversion signals that magnetism is not simply templated by the moiré pattern, but instead emerges from a collective competition between exchange, magnetic anisotropy and Dzyaloshinskii–Moriya interactions, all subtly tuned by relative layer rotation. Large-scale spin dynamics simulations support this picture, revealing the stabilization of extended, Néel-type antiferromagnetic skyrmions spanning multiple moiré cells.

The implications extend beyond fundamental magnetism. Skyrmionic textures are attractive for information technologies because they are compact, topologically protected and movable with minimal energy. Generating them through twist alone, without lithography, heavy metals or strong currents, offers a clean, geometry-based route toward low-power spintronic architectures.

By introducing the concept of super-moiré spin order, the work reframes twist engineering as a multiscale tool: atomic alignment gives rise to mesoscale topology. This challenges the prevailing picture that moiré physics is purely local and establishes twist angle as a powerful thermodynamic control parameter that tunes exchange, anisotropy and chiral interactions to stabilize topological phases.

Practically, such large, robust Néel-type skyrmionic textures are suited for device integration: their mesoscale size improves detectability and addressability, while their topological protection and insulating host material promise ultra-low dissipation operation. As researchers continue to explore the rich interplay between geometry and quantum interactions, such emergent behaviour may become central to the quest for energy-efficient, post-CMOS computing platforms.

Dr Elton Santos, Reader in Theoretical/Computational Condensed Matter Physics, University of Edinburgh, whose team led the modelling aspect of the project, said: “This discovery shows that twisting is not just an electronic knob, but a magnetic one. We’re seeing collective spin order self-organize on scales far larger than the moiré lattice. It opens the door to designing topological magnetic states simply by controlling angle, which is a remarkably simple handle with profound practical consequences.”

For further information and press enquiries, please contact: Rhona Crawford, Press and PR Office, University of Edinburgh. Email: rhona.crawford@ed.ac.uk

 

 

END