Images of a spin-torque-driven magnetic nano-oscillator
Xiaowei Yu,Vlad Pribiag,Yves Acremann,Ashwin Tulapurkar,Tolek Tyliszczak,Kang Wei Chou,Björn Bräuer,Zhi-Pan Li,O. J. Lee,P. G. Gowtham,Daniel C. Ralph,Robert A. Buhrman,Joachim Stöhr +12 more
TLDR
This work presents the first space- and time-resolved images of the spin-torque-induced steady-state oscillation of a magnetic vortex in a spin-valve nanostructure and finds that the vortex structure in a nanopillar is considerably more complicated than the 2D idealized structure often-assumed.Abstract:
We present the first space- and time-resolved images of the spin-torque-induced steady-state oscillation of a magnetic vortex in a spin-valve nanostructure. We find that the vortex structure in a nanopillar is considerably more complicated than the 2D idealized structure often-assumed, which has important implications for the driving efficiency. The sense of the vortex gyration is uniquely determined by the vortex core polarity, confirming that the spin-torque acts as a source of negative damping even in such a strongly nonuniform magnetic system. The orbit radius is $\ensuremath{\sim}10\text{ }\text{ }\mathrm{nm}$, in agreement with micromagnetic simulations.read more
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Journal ArticleDOI
The 2014 Magnetism Roadmap
Robert Stamps,Stephan Breitkreutz,Johan Åkerman,Johan Åkerman,Andrii V. Chumak,Yoshichika Otani,Yoshichika Otani,Gerrit E. W. Bauer,Gerrit E. W. Bauer,Jan Ulrich Thiele,Martin Bowen,Sara A. Majetich,Mathias Kläui,Ioan Lucian Prejbeanu,Ioan Lucian Prejbeanu,Bernard Dieny,Bernard Dieny,Nora Dempsey,Burkard Hillebrands +18 more
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Book ChapterDOI
Spin-Torque Oscillators
Joo-Von Kim,Joo-Von Kim +1 more
TL;DR: In this paper, the theoretical aspects of magnetization oscillations driven by spin torques, such as spin waves and vortex gyration, are presented in detail and key experimental results are highlighted.
Journal ArticleDOI
Direct observation and imaging of a spin-wave soliton with p-like symmetry
Stefano Bonetti,Roopali Kukreja,Zhao Chen,Zhao Chen,Ferran Macià,Joan Manel Hernàndez,Anders Eklund,Dirk Backes,Josef Frisch,Jordan A. Katine,Gunnar Malm,Sergei Urazhdin,Andrew D. Kent,Joachim Stöhr,Hendrik Ohldag,H. A. Dürr +15 more
TL;DR: Micromagnetic simulations explain the measurements and reveal that the symmetry of the soliton can be controlled by magnetic fields, which broadens the understanding of spin-wave dynamics at the nanoscale, with implications for the design of magnetic nanodevices.
Journal ArticleDOI
Direct dynamic imaging of non-adiabatic spin torque effects
TL;DR: It is shown that enhanced magnetic imaging under dynamic excitation can be used to differentiate between non-adiabatic spin-torque and extraneous influences, providing a robust method to determine the non-adiabaticspin torque parameter β=0.15±0.02 with unprecedented precision, independent of external effects.
Journal ArticleDOI
Higher order vortex gyrotropic modes in circular ferromagnetic nanodots
TL;DR: In this paper, the spin excitation modes related to the thickness dependent vortex core gyrotropic dynamics were detected experimentally in the gigahertz frequency range in the absence of external magnetic field, and it was shown that these exchange dominated modes are flexure oscillations of the vortex core string with n = 0, 1,2 nodes along the dot thickness.