2023/04/12 by Sheng Jiang, Jiang, Sheng, Sunjae Chung +15
Engineering · Physics and Astronomy · #Applied Physics (physics.app-ph) #Characterization and Applications of Magnetic Nanoparticles #FOS: Physical sciences #Magnetic properties of thin films #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.2304.05825
openalex publication_date 2023/04/12 · openalex created_date 2023/04/15 · openalex updated_date 2026/07/28
Magnetic droplets are nanoscale, non-topological, magnetodynamical solitons that can be nucleated in spin torque nano-oscillators (STNOs) or spin Hall nano-oscillators (SHNOs). All theoretical, numerical, and experimental droplet studies have so far focused on the free layer (FL), and any additional dynamics in the reference layer (RL) have been entirely ignored. Here we show, using all-perpendicular STNOs, that there is not only significant magnetodynamics in the RL, but the reference layer itself can host a droplet coexisting with the FL droplet. Both droplets are observed experimentally as stepwise changes and sharp peaks in the dc and differential resistance, respectively. Whereas the single FL droplet is highly stable, the coexistence state exhibits high-power broadband microwave noise. Micromagnetic simulations corroborate the experimental results and reveal a strong interaction between the droplets. Our demonstration of strongly interacting and closely spaced droplets offers a unique platform for fundamental studies of highly non-linear soliton pair dynamics.