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Title: Spin wave localization in one-dimensional magnonic microcavity comprising yttrium iron garnet

Abstract

We demonstrate the localization of magnetostatic surface waves, i.e., spin waves, in a one-dimensional magnonic microcavity substantialized with periodical conductivity modulation. The narrow localized state is observed inside band gaps and is responsible for a sharp transmission peak. The experimental results strongly agree with the theoretical prediction made with the shape magnetic anisotropy of the propagating medium composed of yttrium iron garnet taken into account.

Authors:
; ;  [1]
  1. Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibari-Ga-Oka, Tempaku, Toyohashi, Aichi 441-8580 (Japan)
Publication Date:
OSTI Identifier:
22314342
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; FERRITE GARNETS; FORECASTING; MODULATION; ONE-DIMENSIONAL CALCULATIONS; PERIODICITY; SPIN WAVES; WAVE PROPAGATION; YTTRIUM

Citation Formats

Kanazawa, Naoki, Goto, Taichi, E-mail: goto@ee.tut.ac.jp, and Inoue, Mitsuteru. Spin wave localization in one-dimensional magnonic microcavity comprising yttrium iron garnet. United States: N. p., 2014. Web. doi:10.1063/1.4893936.
Kanazawa, Naoki, Goto, Taichi, E-mail: goto@ee.tut.ac.jp, & Inoue, Mitsuteru. Spin wave localization in one-dimensional magnonic microcavity comprising yttrium iron garnet. United States. doi:10.1063/1.4893936.
Kanazawa, Naoki, Goto, Taichi, E-mail: goto@ee.tut.ac.jp, and Inoue, Mitsuteru. 2014. "Spin wave localization in one-dimensional magnonic microcavity comprising yttrium iron garnet". United States. doi:10.1063/1.4893936.
@article{osti_22314342,
title = {Spin wave localization in one-dimensional magnonic microcavity comprising yttrium iron garnet},
author = {Kanazawa, Naoki and Goto, Taichi, E-mail: goto@ee.tut.ac.jp and Inoue, Mitsuteru},
abstractNote = {We demonstrate the localization of magnetostatic surface waves, i.e., spin waves, in a one-dimensional magnonic microcavity substantialized with periodical conductivity modulation. The narrow localized state is observed inside band gaps and is responsible for a sharp transmission peak. The experimental results strongly agree with the theoretical prediction made with the shape magnetic anisotropy of the propagating medium composed of yttrium iron garnet taken into account.},
doi = {10.1063/1.4893936},
journal = {Journal of Applied Physics},
number = 8,
volume = 116,
place = {United States},
year = 2014,
month = 8
}
  • Magnonic crystals (MCs) are key components for spin wave manipulation. MCs realized with periodically metallized surfaces have an advantage in ease of the fabrication, but the effect of the metal thickness has not been studied well. In this work, the metal thickness dependence on the transmission spectra of localized mode spin waves was investigated. The metal thickness over half of the skin depth was necessary to prevent strong attenuation of spin waves.
  • We study experimentally with submicrometer spatial resolution the propagation of spin waves in microscopic waveguides based on the nanometer-thick yttrium iron garnet and Pt layers. We demonstrate that by using the spin-orbit torque, the propagation length of the spin waves in such systems can be increased by nearly a factor of 10, which corresponds to the increase in the spin-wave intensity at the output of a 10 μm long transmission line by three orders of magnitude. We also show that, in the regime, where the magnetic damping is completely compensated by the spin-orbit torque, the spin-wave amplification is suppressed by themore » nonlinear scattering of the coherent spin waves from current-induced excitations.« less
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  • Ferromagnetic resonance in a polished 0.047-cm-radius sphere of gallium-doped yttrium iron garnet is studied at 1.3 GHz in a magnetic field of 460 G. A second-order Suhl instability is observed, owing to the nonlinear coupling of the precessing uniform magnetization with spin waves. This is detected by the onset of auto-oscillations of the magnetization. One of these modes with frequency roughly-equal16 kHz corresponds to the lowest spherical dimensional resonance of a packet of spin waves of small wave vector and long lifetime (roughly-equal10/sup 3/ cycles). From real-time signals, spectral analysis, and return maps this mode is found to display chaoticmore » dynamics as the driving rf field is increased: thresholds for the onset of period-doubling bifurcations, chaos, and periodic windows. Some observed return maps bear resemblance to the two-dimensional area-preserving quadratic map of Henon. The system has several attractors and displays ''solid-state turbulence,'' analogous to that in fluids.« less
  • The second-order spin-wave instability threshold in yttrium-iron-garnet single-crystal thin films has been investigated under conditions of ferromagnetic resonance (FMR). The samples were (111) etched circular films of 500 ..mu..m diam and 5.1 ..mu..m thickness, grown on gadolinium gallium garnet substrates by liquid-phase epitaxy. The pulsed microwave power FMR absorption curves were measured by standard signal averaging techniques at 9.18 GHz and room temperature for three different perpendicular pumping configurations: (1) in-plane static field and out-of-plane microwave field, (2) mutually perpendicular in-plane static and microwave fields, and (3) out-of-plane static field and in-plane microwave field. The experimental results show that themore » upsweep and downsweep FMR curves for lower pulsed microwave powers at low duty cycle of 1% are identical, but there are foldover effects in the FMR profiles at higher powers. Theoretical expressions for the instability threshold for these three configurations were obtained by extending previous theories. The calculated thresholds are in good agreement with the experimental results for configurations (1) and (2). The results for configuration (3) indicate the presence of a true foldover effect, also consistent with instability theory.« less