Nonlinear spin waves in non-uniform potentials
Final Report Abstract
The aim of this project is to study the emission of high-frequency waves of magnetization (spin waves) by nano-devices based on the spin-transfer torque phenomenon. This emission enables the utilization of spin-torque devices as nano-sources of spin waves for future-generation integrated electronic devices, where spin waves are used as a medium for nano-scale transmission and processing of signals – the so-called magnonic devices. Additionally, the emission of spin waves enables the dynamic coupling in ensembles of microwave magnetic nano-oscillators resulting in the improvement of their characteristics. Within the project, we addressed different approaches to the achievement of efficient spin-wave emission by spin-torque nano-devices and directional nano-scale transmission of these waves. In particular, we demonstrated that these goals can be achieved by utilizing dipolar magnetic fields of nano-patterns integrated with the spin-torque devices. By using these fields one can locally modify the magnetic-field potentials and achieve efficient spectral matching of spintorque devices with nanosized spin-wave guiding structures. The project has also resulted in the experimental demonstration of novel type of spin-torque nano-devices driven by pure spin current not accompanied by the transfer of electrical charge, which allows one to reduce the detrimental heating and electromigration effects typical for traditional spin-torque devices. In addition to that, the geometry of the novel devices is much better suited for magnonic applications compared to that of traditional devices.
Publications
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“Micromagnetic studies of autooscillation modes in spin-Hall nano-oscillators”, Appl. Phys. Lett. 104, 042407 (2014)
H. Ulrichs, V. E. Demidov, and S. O. Demokritov
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“Nanomagnonic devices based on the spin-transfer torque,” Nature Nanotech. 9, 509-513 (2014)
S. Urazhdin, V. E. Demidov, H. Ulrichs, T. Kendziorczyk, T. Kuhn, J. Leuthold, G. Wilde and S. O. Demokritov
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“Dipolar field-induced spin-wave waveguides for spin-torque magnonics,” Appl. Phys. Lett. 106, 022403 (2015)
V. E. Demidov, S. Urazhdin, A. Zholud, A. V. Sadovnikov, and S. O. Demokritov
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“Magnonic waveguides studied by microfocus Brillouin light scattering,” IEEE Trans. Mag. Volume: 51, Issue: 4, April 2015
V. E. Demidov and S. O. Demokritov
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“Spin-current nano-oscillator based on nonlocal spin injection,” Scientific Reports volume 5, Article number: 8578 (2015)
V. E. Demidov, S. Urazhdin, A. Zholud, A. V. Sadovnikov, A. N. Slavin, and S. O. Demokritov
