Mode locking between helimagnetism and ferromagnetism

Journal article

Non-collinear spin textures, such as spin spirals and skyrmions, exhibit rich emergent physics in their spin dynamics. Nevertheless, the potential to utilize their distinctive spin resonance characteristics for on-chip microwave magnonic applications is rarely explored. Here we demonstrate microwave emission and mode coupling from the resonating spin spiral lattice in a Cu₂OSeO₃/Pt/NiFe heterostructure. We use time-resolved resonant elastic X-ray scattering to visualize the exact vectorial spin precession modes from the two magnetic species in real time. Our results show that the ferromagnetic NiFe layer dynamically captures the excitation modes of the conical order in helimagnet Cu₂OSeO₃. The off-resonance NiFe spin precession is phase locked to the helimagnet with a fixed offset, thereby presenting distinct chiral dynamics. This demonstrates that the magnons produced in the process—referred to as helimagnons—can wirelessly transmit spin information at gigahertz frequencies, opening new avenues for on-chip microwave magnonics.

Authors: Chen, J; Jin, H; Arnold, EL; van der Laan, G; Hesjedal, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Nature
• Journal: Nature Physics
• Volume: 22
• Issue: 2
• Pages: 259-264
• Publication date: 2026-01-28
• Acceptance date: 2025-11-25
• DOI: 10.1038/s41567-025-03148-5
• EISSN: 1745-2481
• ISSN: 1745-2473
• Language: English