Magnetization switching by spin current induced by ultra short pulse laser

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K18878
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Electrical and electronic engineering and related fields
• Research Institution: Nagoya University
• Principal Investigator: Kato Takeshi 名古屋大学, 工学研究科, 准教授 (50303665)
• Co-Investigator(Kenkyū-buntansha): 岩田 聡 名古屋大学, 未来材料・システム研究所, 教授 (60151742) ; 大島 大輝 名古屋大学, 未来材料・システム研究所, 特任助教 (60736528)
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: 電子・電気材料

Outline of Final Research Achievements

In order to observe spin current generation by the ultra short pulse laser and the magnetization switching by the spin current, two experiments, 1) spin current injection to Au from 3d transition metal Fe and 2) magnetization switching of GdFeCo by injecting the spin current, were carried out. Fe thickness dependence of the damping constant of Fe showed the Au layer has useful properties as a spin current conductor. When the spin current injected to GdFeCo, the moment of GdFeCo feels large equivalent magnetic field around the compensation composition. Moreover, it was found that the injected spin current exerts a torque to only FeCo moment.

Free Research Field

磁性薄膜工学

Academic Significance and Societal Importance of the Research Achievements

本研究は超短パルス光誘起スピン流による磁化反転に挑戦するものであり，これまで電流のみで可能であったスピン流磁化反転が光を用いても可能であることを示す萌芽的な研究である．今回，Auという材料がスピン流伝送に有用な材料であること，希土類－遷移金属合金であるGdFeCoでは補償組成付近でスピン流による磁化反転が容易に行えることが分かった．今後，これらを組み合わせ，ポンプ光照射によるGdFeCo膜のスピン流磁化反転が可能となると考えられる．