固体中の単一のエリオンから区別できない電気通信帯の光子
Salim Ourari1, Łukasz Dusanowski1, Sebastian P Horvath1
1Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA.
Nature
|August 30, 2023
まとめ
研究者らは量子リピーターの 稀土イオンのスペクトル拡散を減少させた. CaWO4結晶のエルビウムイオンによるこの突破は より堅牢な量子通信ネットワークを可能にします
科学分野:
- 量子コミュニケーション
- 固体物理学
- 量子情報科学
背景:
- 原子の欠陥は量子リピーターネットワークにとって 極めて重要です
- 稀土イオン,特にEr3+は,光学的移行により,通信帯域の量子通信に有望である.
- 光学スペクトル拡散は区別がつかない単光子の生成を妨げ,リピーターノードの開発を制限しています.
研究 の 目的:
- 量子リピーターのアプリケーションのための希土イオンにおける光学スペクトル拡散を大幅に減らす.
- 遠距離量子通信のための 区別できない単光子の生成を可能にする
主な方法:
- Er3+イオンをCaWO4結晶に埋め込み,非極性サイト対称性,低核スピン脱合性,背景稀土イオンがないために選択した.
- 浅いインプラントイオンを高パーセル因子を持つナノフォトニック空洞に結合する.
- 光学線幅,長期スペクトル拡散,およびスピンリラクゼーション時間の特徴.
主要な成果:
- シングルスキャンで150 kHzの光線幅と63 kHzの長期拡散で,光学スペクトル拡散が著しく減少した.
- 36kmの遅延後に連続して発射された光子間の80%の可視性を持つHong-Ou-Mandel干渉を観測した.
- 測定された長いスピンリラクゼーション時間 (T1,s = 3.7 s,T2,s > 200 μs) で,T2,sは核スピンではなく不純物によって制限されます.
結論:
- 開発されたEr3+ドーピングされたCaWO4システムは,光学スペクトル拡散を大幅に減少させ,量子リピートターの主要な制限を克服します.
- 観測された区別がつかない光子生成と長いスピンコヒーレンス時間は,実用的な電気通信帯域量子リピーターネットワークに向けた重要な進歩を表しています.
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