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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：53 パーセンタイル：88.06(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.
安 東秀*; Vasyuchka, V. I.*; 内田 健一*; Chumak, A. V.*; 山口 和也*; 針井 一哉; 大江 純一郎*; Jungfleisch, M. B.*; 梶原 瑛祐*; 安立 裕人; et al.
Nature Materials, 12(6), p.549 - 553, 2013/06
被引用回数：122 パーセンタイル：96.28(Chemistry, Physical)In this paper, we show a magnetically controllable heat flow caused by a spin-wave current. The direction of the flow can be switched by applying a magnetic field. When microwave energy is applied to a region of ferrimagnetic Y
Fe
O
, an end of the magnet far from this region is found to be heated in a controlled manner and a negative temperature gradient towards it is formed. This is due to unidirectional energy transfer by the excitation of spin-wave modes without time-reversal symmetry and to the conversion of spin waves into heat. The magnetically controlled remote heating we observe is directly applicable to the fabrication of a heat-flow controller.
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：47 パーセンタイル：86.08(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：235 パーセンタイル：98.39(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.
