Realization of ultra-fast and low-power-consumption method for magnetization control utilizing quantum effects of ferromagnetic materials

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21961
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Le Duc Anh 東京大学, 大学院工学系研究科(工学部), 助教 (50783594)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: Fe系強磁性半導体 / 超高速磁化制御 / 強磁性量子井戸 / 波動関数制御法 / ポンプアンドプローブ法

Outline of Final Research Achievements

In this research, in order to realize an ultrafast control of magnetic properties of ferromagnets, we proposed and successfully demonstrated a new method by controlling the carrier wavefunction in low-dimensional ferromagnetic structures. In the demonstration experiment using a pump-and-probe method, we were able to induce a magnetization enhancement in an unprecedentedly short time scale of 600 fs in N-type ferromagnetic semiconductors (FMS) (In,Fe)As quantum wells, which was caused by the ultrafast changing of the electron wavefunctions upon the irradiation of a fs-pulse of the pumping laser. Furthermore, we developed some other low-dimensional ferromagnetic structures of Fe-doped FMSs such as ferromagnetic superlattices and quantum dots, to which the proposed ultrafast magnetization control method can possibly be applied. The realization of the world's fastest magnetization enhancement here promisingly leads to the next-generation of ultra-high-speed, low-consumption spin devices.

Free Research Field

スピントロニクス

Academic Significance and Societal Importance of the Research Achievements

次世代の電子デバイスは超高速と低消費電力が強く要求される中、電子のスピン自由度を活用スピンデバイスとスピンに基づいた情報処理が有力候補になりつつある。スピンデバイスの基本操作である磁化制御を如何により高速、低電力で実現できるかが大きな課題である。本萌芽研究ではその究極的な方法として低次元強磁性構造の波動関数制御法を提案し、現在の制御法より1000倍も速い世界最速の磁化増大制御の実証まで成功した。この新制御法がより広範囲で応用できれば次世代の超高速低消費スピンデバイスに繋がり現存の情報処理技術に革新的な進歩をもたらせると期待できる。