Perfectly harmonic spin cycloid and multi-Q textures in the Weyl semimetal GdAlSi
A fundamental question in condensed matter physics concerns how topological electronic states are influenced by many-body correlations, and magnetic Weyl semimetals represent an important material platform to address this problem. However, the magnetic structures realized in these materials are limited, and in particular, no clear example of an undistorted helimagnetic state has been definitively identified. Here, we report clear evidence of a harmonic helimagnetic cycloid with an incommensurate magnetic propagation vector Q in the Weyl semimetal GdAlSi via resonant elastic X-ray scattering, including rigorous polarization analysis. This cycloidal structure is consistent with the Dzyaloshinskii-Moriya interaction prescribed by the polar crystal structure of GdAlSi. Upon applying a magnetic field, the cycloid undergoes a transition to a novel multi-Q state. This field-induced, noncoplanar texture is consistent with our numerical spin model, which incorporates the Dzyaloshinskii-Moriya interaction and, crucially, anisotropic exchange interactions. The perfectly harmonic Weyl helimagnet GdAlSi serves as a prototypical platform to study electronic correlation effects in periodically modulated Weyl semimetals.
Authors
- Óscar Fabelo (ORCID: https://orcid.org/0000-0001-6452-8830)
- Jan Masell (ORCID: https://orcid.org/0000-0002-9951-4452)
- Yasujiro Taguchi (ORCID: https://orcid.org/0000-0003-1896-699X)
- R. Yamada (ORCID: https://orcid.org/0000-0002-5078-059X)
- H. Ohsumi (ORCID: https://orcid.org/0000-0002-6418-8984)
- K. Gautam (ORCID: https://orcid.org/0000-0002-2489-6441)
- Y. Takahashi (ORCID: https://orcid.org/0000-0003-3630-9782)
- Shunsuke Kitou (ORCID: https://orcid.org/0000-0002-2349-140X)
- Masashi Tokunaga (ORCID: https://orcid.org/0000-0002-1401-9381)
- Yoshihiro Okamura (ORCID: https://orcid.org/0000-0002-4987-7095)
- Masaki Gen (ORCID: https://orcid.org/0000-0003-1362-7323)
- Priya R. Baral (ORCID: https://orcid.org/0000-0002-9755-6165)
- Max Hirschberger (ORCID: https://orcid.org/0000-0002-1780-1619)
- Yuiga Nakamura (ORCID: https://orcid.org/0000-0003-3696-0997)
- Y K Tanaka
- Kentaro Shoriki (ORCID: https://orcid.org/0000-0002-1321-0301)
- Yuki Ishihara (ORCID: https://orcid.org/0000-0003-4114-9701)
- R. Arita
- Maurice Colling
- Hironori Nakao
- Akiko Kikkawa
- Ryo Misawa
- Juba Bouaziz
- Yoshinori Tokura
- Hajime Sagayama
- Taka-hisa Arima
- Satoru Hayami
Institutions
- Karlsruhe Institute of Technology (DE)
- High Energy Accelerator Research Organization (JP)
- Tokyo University of Science (JP)
- Norwegian University of Science and Technology (NO)
- Hokkaido University (JP)
- SPring-8 (JP)
- Japan Synchrotron Radiation Research Institute (JP)
- Institut Laue-Langevin (FR)
- RIKEN Center for Emergent Matter Science (JP)
- The University of Tokyo (JP)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-02-23
- DOI
- https://doi.org/10.1038/s41467-026-69452-7
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Mazda Foundation
- Alexander von Humboldt-Stiftung
- Yashima Environment Technology Foundation
- Deutsche Forschungsgemeinschaft
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Hattori Hokokai Foundation
- Inamori Foundation
- Casio Science Promotion Foundation
- Foundation for Promotion of Material Science and Technology of Japan
- Murata Science Foundation
- Yazaki Memorial Foundation for Science and Technology
- Toray Science Foundation
- Japan Society for the Promotion of Science
- Japan Science and Technology Agency
- RIKEN
- Core Research for Evolutional Science and Technology
- Precursory Research for Embryonic Science and Technology