Watching solitons evolve – in real & reciprocal space!!

We're happy to share our latest paper on "Field-induced condensation of π to 2π soliton lattices in chiral magnets" by M. Winter, A. Pignedoli, M. C. Rahn and co-workers. A standout feature of this study is that we bring together two of the most powerful probes for magnetic textures — resonant elastic X-ray scattering (REXS) and transmission electron microscopy (TEM) — on one and the same sample , giving us a rare, cross-validated view of the physics in both real and reciprocal space.

Chiral soliton lattices are periodic arrays of magnetic "kinks" that arise when the Dzyaloshinskii–Moriya interaction, magnetocrystalline anisotropy, and an applied field compete. While these textures are well understood in monoaxial helimagnets, their behavior in materials with direction-dependent chirality has remained largely unexplored — and that is exactly the gap we set out to close.

Studying the non-centrosymmetric Heusler compound Mn_1.4PtSn, we combined Lorentz TEM, REXS, and micromagnetic simulations to make a surprising observation: the magnetic ground state is a π-soliton lattice rather than the expected spiral phase, and it condenses smoothly into a classical 2π-soliton lattice as an out-of-plane field is increased.

This crossover is driven by the interplay of uniaxial anisotropy and magnetostatic interactions and is well captured by a double sine-Gordon model, giving a clear and intuitive picture of the underlying physics. Importantly, the framework is not restricted to this one material: it extends to thin films with D_2d, S₄, C_nv, or C_n symmetries, offering a unifying route to engineer magnetic phase diagrams in chiral systems, with clear implications for soliton-based spintronics and topological transport .

This study was a broad international collaboration spanning the MPI CPfS, TUD Dresden, IFW Dresden, the Helmholtz Association, the Universities of Duisburg-Essen, Augsburg, and Oxford, and the Diamond, ALBA, and HZB large-scale facilities.

Original pubilcation:
Field-induced condensation of π to 2π soliton lattices in chiral magnets, M. Winter, A. Pignedoli, M. C. Rahn, A. S. Sukhanov, B. Achinuq, J. R. Bollard, M. Azhar, K. Everschor-Sitte, D. Pohl, S. Schneider, A. Tahn, V. Ukleev, M. Valvidares, A. Thomas, D. Wolf, P. Vir, T. Helm, G. van der Laan, T. Hesjedal, J. Geck, C. Felser & B. Rellinghaus 
Commun. Phys. 9, 264 (2026)