In-plane field angle dependence of mutually synchronized constriction based spin Hall nano-oscillators

• We study mutual synchronization phenomena in multiple nanoconstriction-based SHNOs under weak in-plane fields down to μ0H = 30 mT and investigate the angular dependence of the synchronization condition. We compare double nanoconstriction and multiple nanoconstrictions with different spacings of 300 and 900 nm between the constrictions. For all the tested devices, we observe clear evidence of mutual synchronization of individual nanoconstrictions (NCs) only for angles smaller than a critical angle. This critical angle is higher for the 300 nm spacing than for the 900 nm spacing as a result of the stronger synchronization arising from the shorter distance. Direct inspection of the spin waves using μ-BLS maps confirms synchronization of the double nanoconstrictions. Alongside the synchronization, we observe a strong second harmonic that could be interpreted as a sign that the synchronization is mediated by the propagation of the second harmonic of the spin waves. Micromagnetic simulation explains the synchronization at the lower angles by the direction of the spatial profile of the modes and confirms the role of exchange coupling in the synchronization of nanoconstriction-based SHNOs.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Keyword

Synchronization

in-plane field

spin Hall effect

nano-oscillators

SHNO

Physics

Fysik

Publication and Content Type

vet (subject category)

ovr (subject category)