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arXiv · 2006.02151

Giant voltage control of spin Hall nano-oscillator damping

Himanshu Fulara·Mohammad Zahedinejad·Roman Khymyn·Mykola Dvornik·Shunsuke Fukami·Shun Kanai·Hideo Ohno·Johan Åkerman
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Abstract

Spin Hall nano-oscillators (SHNOs) are emerging spintronic devices for microwave signal generation and oscillator based neuromorphic computing combining nano-scale footprint, fast and ultra-wide microwave frequency tunability, CMOS compatibility, and strong non-linear properties providing robust large-scale mutual synchronization in chains and two-dimensional arrays. While SHNOs can be tuned via magnetic fields and the drive current, neither approach is conducive for individual SHNO control in large arrays. Here, we demonstrate electrically gated W/CoFeB/MgO nano-constrictions in which the voltage-dependent perpendicular magnetic anisotropy, tunes the frequency and, thanks to nano-constriction geometry, drastically modifies the spin-wave localization in the constriction region resulting in a giant 42 % variation of the effective damping over four volts. As a consequence, the SHNO threshold current can be strongly tuned. Our demonstration adds key functionality to nano-constriction SHNOs and paves the way for energy-efficient control of individual oscillators in SHNO chains and arrays for neuromorphic computing.

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Himanshu Fulara, Mohammad Zahedinejad, Roman Khymyn, Mykola Dvornik, Shunsuke Fukami, Shun Kanai, Hideo Ohno, Johan Åkerman. 2020-06-03. Giant voltage control of spin Hall nano-oscillator damping. https://doi.org/10.1038/s41467-020-17833-x

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