Tcの上の乱れた超伝導体におけるスペクトルギャップのないクーパーペアリングの直接的証拠
Koen M Bastiaans1, Damianos Chatzopoulos1, Jian-Feng Ge1
1Leiden Institute of Physics, Leiden University, 2333 CA Leiden, Netherlands.
Science (New York, N.Y.)
|October 28, 2021
まとめ
プレフォームド・クーパー・ペアは,臨界温度を超えるチタン・ニトリドの超伝導体の中に存在する. この発見は,ノイズスペクトロスコーピーを用いて観察され,ペアリングされた電子を通して電荷を運ぶユニークな金属状態を明らかにします.
科学分野:
- 凝縮物質物理学
- 超伝導性の研究
- 材料科学
背景:
- 臨界温度 (Tc) 以上の前形クーパーペアの存在は,超伝導性における理論的概念である.
- 非従来の,インターフェイス,および無秩序な超伝導体におけるプリフォームドクーパーペアの直接的な実験的証拠は限られている.
研究 の 目的:
- Tc 以上 の 温度 で 乱れ た 超伝導体 の 中 に,前編成 の クーパー ペア の 存在 を 実験 的 に 調べる.
- 高い温度下でのニトリドの電子状態を特徴づけるために.
主な方法:
- タイタニウム窒素の電子特性を探査するためにスキャニングトンネルノイズスペクトロスコーピーを利用しました.
- ショットノイズの強化を分析し,有効な電荷キャリアの性質を決定した.
- 温度の関数としてスペクトルギャップの振る舞いを測定した.
主要な成果:
- プレフォームド・クーパー・ペアが,チタン・ニトリドでTcより著しく高い温度で持続する証拠を観測した.
- ショットノイズの測定は,ペアリングされた電子 (二つの電子電荷) と一致する有効電荷を示した.
- 温度が上昇するにつれて,光譜のギャップは埋まるのではなく,埋まることがわかりました.
結論:
- クーパー・ペアの存在を証明した 超伝導体の臨界温度を超えた状態で
- 偽ギャップなしで電荷を運ぶペアリングされた電子によって特徴づけられるTc上の新しい電子状態を特定した.
- 超伝導体におけるプレボソニックペアリングの理論を支持する直接的な実験的証拠を提供した.
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