光学的に制御された,コヒーレントダークステートスペクトロスコピーによる核フィールドのロック
Xiaodong Xu1, Wang Yao, Bo Sun
1The H. M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109, USA.
Nature
|June 26, 2009
まとめ
研究者は,量子ドットにおける核スピン変動を抑制し,電子スピン相関時間を大幅に改善しました. このブレークスルーは,新しいフィードバックプロセスを用いて,堅牢な量子論理装置の道を開く.
科学分野:
- 量子情報科学とは,量子情報科学である.
- 凝縮物質物理学 凝縮物質物理学
- 半導体スピントロニクス
背景:
- 半導体量子ドットの単一スピンは,量子コンピューティングの鍵です.
- III-V物質の核スピンは,超微細相互作用によって電子スピンの相関性を破壊する.
- 以前の方法は,核スピンの変動を抑制することに焦点を当てており,同時制御ではありませんでした.
研究 の 目的:
- 量子ドット内の単一のスピンの一貫した制御を達成し,核の変動を抑制します.
- 電子のスピンコヒーレンス時間を高める方法を示す.
- 核スピン環境の再現可能な準備を可能にするために.
主な方法:
- コヘレントダークステートスペクトロスコピーは,電子のスピン脱相時間 (T(2) *) を測定します.
- ホールスピンアシストダイナミックな核スピン極化フィードバックプロセスを利用します.
- 核フィールドのロックを実証するために3つのレーザー測定を使用します.
主要な成果:
- 核フィールドの波動は,熱値よりはるかに下まで抑制された.
- 電子スピン脱相時間 (T(2) *) は著しく増加した.
- 抑制の原因として,ホールスピン補助フィードバックメカニズムが特定されました.
- レーザーパラメータによって決定された核フィールドのロックが達成されました.
結論:
- 電子のスピン相関性を高めるための新しい,シンプルで強力な方法が開発されました.
- この技術は,複雑な"スピン・エコー"タイプの方法を避けています.
- 結果は,核環境を安定させることで,単一のスピンの再現可能な制御と測定を可能にします.
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