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arXiv · 1802.05548

Damping's effect on the magnetodynamics of spin Hall nano-oscillators

Yuli Yin·Philipp Dürrenfeld·Mykola Dvornik·Martina Ahlberg·Afshin Houshang·Ya Zhai·Johan Åkerman
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Abstract

We study the impact of spin wave damping ($α$) on the auto-oscillation properties of nano-constriction based spin Hall nano-oscillators (SHNOs). The SHNOs are based on a 5 nm Pt layer interfaced to a 5 nm Py$_{100-x-y}$Pt$_{x}$Ag$_{y}$ magnetic layer, where the Pt and Ag contents are co-varied to keep the saturation magnetization constant (within 10 %), while $α$ varies close to a factor of three. We systematically investigate the influence of the Gilbert damping on the magnetodynamics of these SHNOs by means of electrical microwave measurements. Under the condition of a constant field, the threshold current scales with the damping in the magnetic layer. The threshold current as a function of field shows a parabolic-like behavior, which we attribute to the evolution of the spatial profile of the auto-oscillation mode. The signal linewidth is smaller for the high-damping materials in low magnetic fields, although the lowest observed linewidth was measured for the alloy with least damping.

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Yuli Yin, Philipp Dürrenfeld, Mykola Dvornik, Martina Ahlberg, Afshin Houshang, Ya Zhai, Johan Åkerman. 2018-02-15. Damping's effect on the magnetodynamics of spin Hall nano-oscillators. https://arxiv.org/abs/1802.05548

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