高温超伝導体YBa2Cu3Oyにおける磁場誘発の電荷帯の順序
Tao Wu1, Hadrien Mayaffre, Steffen Krämer
1Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.
Nature
|September 9, 2011
まとめ
高い磁場は,YBa(2) Cu(3) O(yの銅酸化物平面に電荷の順序を誘導し,高過渡温度超伝導体における電荷の順序の固有の傾向を明らかにします. この発見は,超伝導性と電子秩序の間の競争を明確にします.
科学分野:
- 凝縮物質物理学 凝縮物質物理学
- マテリアルサイエンス 材料科学
- 固体化学 固体化学
背景:
- 銅酸化物における高過渡温度 (Tc) 超伝導性は,CuO(2) 平面における電子電荷と関連している.
- 銅酸化物における基礎的な電荷順序の存在とその超伝導性との関係は,依然として議論の余地があります.
- 以前の研究では,超伝導性が YBa(2) Cu(3) O(y) で,電荷の順ではなく,スピンの順に競合することを示唆していました.
研究 の 目的:
- 強い磁場下で,YBa(2) Cu(3) O(y) のCuO(2) 平面における電子秩序の存在と性質を調査する.
- YBa ((2) Cu ((3) O ((y)) に充電順が存在するか,そしてそれが超伝導性と関係しているかを判断する.
- 超伝導性と電子注文現象の間の競争を明確にするために.
主な方法:
- 核磁共振 (NMR) 測定はYBa(2) Cu(3) O(y) について行われました.
- 強い磁場が適用され,超伝導性を不安定化し,電子の秩序を調査した.
- 分析は,電荷密度の静的,一方的な調節を検出することに焦点を当てました.
主要な成果:
- 高い磁場は,YBa(2) Cu(3) O(y) のCuO(2) 平面における静的,片方向の電荷順序を誘導することが判明した.
- この誘導チャージ命令は,スピン命令に伴わないまま発生した.
- 観測された電荷順序は4a周期変調であり,他の銅酸化物におけるストライプ順序に似ており,超伝導性が減少すると出現します.
結論:
- 充電順は,高Tc銅酸化物における超伝導平面の固有傾向であり,YBa(2) Cu(3) O(y) のようなクリーンなサンプルでもそうである.
- 誘導電荷順序は,変換対称性を破り,以前の量子振動の結果を説明します.
- この発見は,特に特定のドーピングレベル (例えば1/8ホールドーピング) の近くに,超伝導性と充電順の間の競争を示唆しています.
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