2020 Fiscal Year Final Research Report
Photoelectric conversion system of spin-information utilizing semiconductor quantum dots
| Project/Area Number |
16H06359
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| Research Category |
Grant-in-Aid for Scientific Research (S)
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| Allocation Type | Single-year Grants |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Hokkaido University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
寒川 誠二 東北大学, 流体科学研究所, 教授 (30323108)
末岡 和久 北海道大学, 情報科学研究院, 教授 (60250479)
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| Project Period (FY) |
2016-05-31 – 2021-03-31
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| Keywords | 半導体量子ドット / スピン光デバイス / 電子スピン注入 / スピンダイナミクス |
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| Outline of Final Research Achievements |
Transporting and injecting spin-polarized electrons into group III-V compound semiconductor quantum dots have been studied aiming at constructing a photoelectric conversion system platform of spin-information. Spin-functional optical/photonic devices have also been studied toward room temperature (RT) operation.
High-efficiency spin injection is realized by tunnel-coupled InGaAs quantum dots with a quantum well. Quantum transport of spin-polarized electrons using a superlattice barrier is demonstrated. Furthermore, a spin-tunnel structure of InAs dots with a GaNAs well demonstrates efficient spin-polarization amplification based on spin blocking of localized electron levels in the GaNAs. As a result, we achieve 90% RT spin polarization. Current spin injection from a ferromagnetic Fe electrode is established at RT. A new electric-field effect device for optical spin-polarization control is also proposed.
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| Free Research Field |
電気電子工学
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| Academic Significance and Societal Importance of the Research Achievements |
光デバイス性能に優れ電子の持つスピン情報の保持が可能な半導体量子ドットへのスピン輸送・注入ダイナミクスの解明は、量子物質科学の重要な知見となる。さらに、半導体中のスピン輸送や室温以上でも高効率に働くスピン偏極の増幅は、通常の実用半導体では不可避なスピン緩和（スピン情報の損失）への抜本的な対策となり、半導体スピントロニクスや量子情報理工学に大きなインパクトを与えうる。そして、電流注入や電界効果による室温動作可能な光スピンデバイスにより、基礎研究に留まっていた半導体光スピントロニクスの実用化への道筋を具体化し、電子や光の状態を利用する超低消費電力の次世代情報システムへの発展を促すことができる。
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