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arXiv · 2402.00586

Spin wave-driven variable-phase mutual synchronization in spin Hall nano-oscillators

Akash Kumar·Avinash kumar Chaurasiya·Victor H. González·Nilamani Behera·Roman Khymyn·Ahmad A. Awad·Johan Åkerman
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Abstract

Spin-orbit torque can drive auto-oscillations of propagating spin wave (PSW) modes in nano-constriction spin Hall nano-oscillators (SHNOs). These modes allow both long-range coupling and the potential of controlling its phase -- critical aspect for nano-magnonics, spin wave logic, and Ising machines. Here, we demonstrate PSW-driven variable-phase coupling between two nano-constriction SHNOs and study how their separation and the PSW wave vector impact their mutual synchronization. In addition to ordinary in-phase mutual synchronization, we observe, using both electrical measurements and phase-resolved $\mu-$Brillouin Light Scattering microscopy, mutual synchronization with a phase that can be tuned from 0 to $\pi$ using the drive current or the applied field. Micromagnetic simulations corroborate the experiments and visualize how the PSW patterns in the bridge connecting the two nano-constrictions govern the coupling. These results advance the capabilities of mutually synchronized SHNOs and open up new possibilities for applications in spin wave logic, unconventional computing, and Ising Machines.

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Akash Kumar, Avinash kumar Chaurasiya, Victor H. González, Nilamani Behera, Roman Khymyn, Ahmad A. Awad, Johan Åkerman. 2024-02-01. Spin wave-driven variable-phase mutual synchronization in spin Hall nano-oscillators. https://doi.org/10.1038/s41567-024-02728-1

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