2021 Fiscal Year Final Research Report
Spin dynamics and realization of a spin laser in (110) semiconductor quantum structures
Project/Area Number |
19K05243
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 29010:Applied physical properties-related
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Research Institution | University of Tsukuba |
Principal Investigator |
Ohno Yuzo 筑波大学, 数理物質系, 教授 (00282012)
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Co-Investigator(Kenkyū-buntansha) |
揖場 聡 国立研究開発法人産業技術総合研究所, エレクトロニクス・製造領域, 主任研究員 (90647059)
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | 半導体スピントロニクス / 半導体レーザー / 分子線エピタキシ / 面発光レーザー |
Outline of Final Research Achievements |
We proposed to use (110) GaAs/AlGaAs superlattice with tunnel coupled quantum wells as a spin transport layer in a semiconductor spintronics devices. As a result of measuring the spin relaxation time of the tunnel-coupled (110) GaAs / AlGaAs superlattice, the spin relaxation time was 0.7 ns or more in the strongly coupled superlattice. As a result of calculations, it was shown that the polarity (4%) necessary for circular polarized lasing can be maintained in a semiconductor laser. As for the growth of high quality (110) GaAs/AlGaAs quantum well, when the substrate temperature is raised to 540 ° C., which is much higher than the crystal growth temperature (~450 ° C.) conventionally reported under high As pressure, a very high-quality quantum well structure with a recombination life of more than 40 ns at room temperature can be obtained. In addition, the spin relaxation time was 6 ns at room temperature, which showed good results.
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Free Research Field |
半導体スピントロニクス
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Academic Significance and Societal Importance of the Research Achievements |
非磁性半導体においてスピン自由度を活用する半導体スピントロニクスでは、スピン輸送技術の確立が必須である。今回トンネル結合量子井戸からなる(110)面GaAs/AlGaAs超格子においてスピン緩和を調べ、波動関数の広がり制御によりスピン緩和を抑制できることが示され、新しいスピン制御技術として有用であることが示された。また、(110)GaAs/AlGaAs分子線エピタキシ結晶成長では、従来報告されている成長温度より100℃近く高い温度で、高As2圧下で成長すると極めて長いキャリア寿命と、十分長いスピン緩和時間が得られることが初めて示され、(110)面結晶成長メカニズムの解明に一石を投じた。
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