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Heussner, F.*; Talmelli, G.*; Geilen, M.*; Heinz, B.*; Br
cher, T.*; Meyer, T.*; Ciubotaru, F.*; Adelmann, C.*; 山本 慧; Serga, A. A.*; et al.
Physica Status Solidi; Rapid Research Letters, 14(4), p.1900695_1 - 1900695_6, 2020/04
被引用回数：31 パーセンタイル：87.61(Materials Science, Multidisciplinary)The emerging field of magnonics employs spin waves and their quanta, magnons, to implement wave-based computing on the micro- and nanoscales. Multi-frequency magnon networks would allow for parallel data processing within single logic elements whereas this is not the case with conventional transistor-based electric logic. However, a lack of experimental proven solutions to efficiently combine and separate magnons of different frequencies has impeded the intensive use of this concept. In this Letter, the experimental realization of a spin-wave demultiplexer enabling frequency-dependent separation of magnetic signals in the GHz range is demonstrated. The device is based on two-dimensional magnon transport in the form of spin-wave beams in unpatterned magnetic films. The intrinsic frequency-dependence of the beam direction is exploited to realize a passive functioning obviating an external control and additional power consumption. This approach paves the way to magnonic multiplexing circuits enabling simultaneous information transport and processing.
Ramos, R.*; 日置 友智*; 橋本 佑介*; 吉川 貴史*; Frey, P.*; Kreil, A. J. E.*; Vasyuchka, V. I.*; Serga, A. A.*; Hillebrands, B.*; 齊藤 英治
Nature Communications (Internet), 10, p.5162_1 - 5162_8, 2019/11
被引用回数：23 パーセンタイル：76.88(Multidisciplinary Sciences)Resonant enhancement of spin Seebeck effect (SSE) due to phonons was recently discovered in Y
Fe
O
(YIG). This effect is explained by hybridization between the magnon and phonon dispersions. However, this effect was observed at low temperatures and high magnetic fields, limiting the scope for applications. Here we report observation of phonon-resonant enhancement of SSE at room temperature and low magnetic field. We observe in Lu
BiFe
GaO an enhancement 700% greater than that in a YIG film and at very low magnetic fields around 10
T, almost one order of magnitude lower than that of YIG. The result can be explained by the change in the magnon dispersion induced by magnetic compensation due to the presence of non-magnetic ion substitutions. Our study provides a way to tune the magnon response in a crystal by chemical doping, with potential applications for spintronic devices.
Schreier, M.*; Bauer, G. E. W.*; Vasyuchka, V.*; Flipse, J.*; 内田 健一*; Lotze, J.*; Lauer, V.*; Chumak, A.*; Serga, A.*; 大門 俊介*; et al.
Journal of Physics D; Applied Physics, 48(2), p.025001_1 - 025001_5, 2015/01
被引用回数：54 パーセンタイル：87.5(Physics, Applied)We carried out a concerted effort to determine the absolute sign of the inverse spin Hall effect voltage generated by spin currents injected into a normal metal. We focus on yttrium iron garnet (YIG)|platinum bilayers at room temperature, generating spin currents by microwaves and temperature gradients. We find consistent results for different samples and measurement setups that agree with theory. We suggest a right-hand-rule to define a positive spin Hall angle corresponding to the voltage expected for the simple case of scattering of free electrons from repulsive Coulomb charges.
Jungfleisch, M. B.*; 安 東秀*; 安藤 和也*; 梶原 瑛祐*; 内田 健一*; Vasyuchka, V. I.*; Chumak, A. V.*; Serga, A. A.*; 齊藤 英治; Hillebrands, B.*
Applied Physics Letters, 102(6), p.062417_1 - 062417_4, 2013/02
被引用回数：48 パーセンタイル：85.77(Physics, Applied)We experimentally demonstrate the manipulation of magnetization relaxation utilizing a temperature difference across the thickness of an yttrium iron garnet/platinum hetero-structure: the damping is either increased or decreased depending on the sign of the temperature gradient. This effect might be explained by a thermally induced spin torque on the magnetization precession. The heat-induced variation of the damping is detected by microwave techniques as well as by a DC voltage caused by spin pumping into the adjacent Pt layer and the subsequent conversion into a charge current by the inverse spin Hall effect.
Sandweg, C. W.*; 梶原 瑛祐*; Chumak, A. V.*; Serga, A. A.*; Vasyuchka, V. I.*; Jungfleisch, M. B.*; 齊藤 英治; Hillebrands, B.*
Physical Review Letters, 106(21), p.216601_1 - 216601_4, 2011/05
被引用回数：247 パーセンタイル：98.42(Physics, Multidisciplinary)We experimentally show that exchange magnons can be detected by using a combination of spin pumping and the inverse spin-Hall effect proving its wavelength integrating capability down to the submicrometer scale. The magnons were injected in a ferrite yttrium iron garnet film by parametric pumping and the inverse spin-Hall effect voltage was detected in an attached Pt layer. The role of the density, wavelength, and spatial localization of the magnons for the spin pumping efficiency is revealed.
