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Contracting vs. exp...
Contracting vs. expanding spin wave bullets in spin Hall nano-oscillators
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- Mazraati, Hamid, Industrial PhD Student, 1989- (författare)
- KTH,Material- och nanofysik
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- Etesami, Seyyed Ruhollah (författare)
- University of Gothenburg
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- Houshang, Afshin (författare)
- University of Gothenburg
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visa fler...
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- Chung, Sunjae (författare)
- KTH,Tillämpad fysik
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- Dvornik, Mykola (författare)
- University of Gothenburg
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- Åkerman, Johan (författare)
- University of Gothenburg
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visa färre...
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(creator_code:org_t)
- Engelska.
- Relaterad länk:
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https://urn.kb.se/re...
Abstract
Ämnesord
Stäng
- We employ electrical measurements complemented by systematic micromagnetic simulations to reveal the complex dynamics of nanoconstriction-based spin Hall nano-oscillators. In particular, depending on the strength and out-of-plane angle of the applied magnetic field, we observe three distinct types of magnetization auto-oscillation: (a) a linear-like mode localized in the vicinity of the nanoconstriction by the demagnetizing field, (b) a further localized “regular” spin wave bullet, and(c) a “large” bullet that fills the entire area of the nanoconstriction. Although it has been assumed for some time that bullets only emerge if the nonlinearity of the system is negative (corresponding to the attraction of magnons), our results demonstrate that, in patterned films, they could be sustained even if the nonlinearity of the system is positive (corresponding to the repulsion of magnons). So, in contrast to the regular spin wave bullet, the auto-oscillation volume of its novel large counterpart enlarges, with the amplitude enhancing their drift stability and, correspondingly, reducing their linewidth. We demonstrate that tuning can be achieved between the observed modes at a fixed external field by changing only the drive current, thanks to the amplitude-dependent nonlinearity of the auto-oscillations. This flexibility of nanopatterned spin Hall nano-oscillators is desirable to achieve synaptic functionality in oscillator-based neuromorphic computing devices.
Ämnesord
- NATURVETENSKAP -- Fysik -- Den kondenserade materiens fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Condensed Matter Physics (hsv//eng)
Nyckelord
- Physics
- Fysik
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