2026-08-11 アルゴンヌ国立研究所（ANL）
Gold microwave antennas on a magnetic thin film transform an input pump signal (pink) into stable, synchronized waves (blue and green) — a visualization of how researchers are learning to control magnons for next-generation computing. (Image by Yi Li and Valentine Novosad, generated using ChatGPT.)
＜関連情報＞
- https://www.anl.gov/article/researchers-generate-spontaneous-magnons-that-synchronize-with-external-signals
- https://www.nature.com/articles/s41467-026-71916-9
パラメトリックポンピングによって誘発される磁気自発振動 Magnonic spontaneous oscillation induced by parametric pumping
Yi Li,Carissa Kiehl,Jinho Lim,Cliff Abbott,Pratap K. Pal,Alex J. Szymczak,Juliang Li,Ralu Divan,Clarence L. Chang,Charudatta Phatak,Dmytro A. Bozhko,Axel Hoffmann & Valentine Novosad
Nature Communications Published:07 July 2026
DOI:https://doi.org/10.1038/s41467-026-71916-9
Abstract
Spontaneous dynamic systems have attracted significant attention for their rich underlying physics such as phase-locking and synchronization. In this work, we report a new mechanism of generating magnetic spontaneous oscillation via parametric pumping. By applying a pump tone to excite propagating spin waves in a yttrium iron garnet delay line, four-wave mixing converts the pump mode into two phase-autonomous propagating magnon modes, i.e. a spontaneous mode with nearly twice the wavenumber of the pump mode and an idler mode with nearly zero wavenumber. This allows us to reliably generate ultrasharp spin wave dynamics with broad frequency tunability from the pump and magnetic field. We show that the spontaneous mode can be phase-locked to a probe tone, similar to an auto-oscillator. Furthermore, the spontaneous dynamics can be used to implement a high-gain magnonic parametric amplifier with a gain up to 40 dB. Our results open a new avenue for studying nonlinear magnonics and synchronization physics in propagating magnon geometry and for developing new magnonic devices.
