Unidirectional spin-wave heat conveyer

一方向性をもつスピン波の熱コンベアー

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; Hillebrands, B.*; 前川 禎通; 齊藤 英治

An, Toshu*; Vasyuchka, V. I.*; Uchida, Kenichi*; Chumak, A. V.*; Yamaguchi, Kazuya*; Harii, Kazuya; Oe, Junichiro*; Jungfleisch, M. B.*; Kajiwara, Yosuke*; Adachi, Hiroto; Hillebrands, B.*; Maekawa, Sadamichi; Saito, Eiji

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 YFeO, 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.