KTaO3 (111) インターフェースにおける二次元超伝導性とアニゾトロプ的輸送
Changjiang Liu1, Xi Yan2,3,4, Dafei Jin5
1Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA. anand@anl.gov changjiang.liu@anl.gov.
Science (New York, N.Y.)
|January 22, 2021
まとめ
超伝導性は,電子ガスの111方向のKTaO3インターフェイスで発生し,2.2ケルビンに達する. カリウムタンタラート (KTaO3) システムでのこの発見は,以前同様の材料で観察されたものより著しく高い.
科学分野:
- 凝縮物質物理学
- 材料科学
- 量子材料について
背景:
- 非従来の量子状態は 物質界面の ユニークな電子構造から生じる
- オキシド間のインターフェイスは,超伝導性を含む新興電子現象をホストすることが知られている.
研究 の 目的:
- 電子ガスの超伝導性の可能性を (111) 方向のKTaO3を含むインターフェースで調査する.
- LaAlO3/SrTiO3のような確立されたシステムとの KTaO3 インターフェースの超伝導特性を比較する.
主な方法:
- KTaO3と絶縁層 (EuOまたはLaAlO3) の間のインターフェースの製造
- クリティカルフィールドと電流-電圧の特性を含む電気輸送測定.
- 超伝導的移行温度を決定する温度依存の抵抗測定
主要な成果:
- EuO/KTaO3 (111) とLaAlO3/KTaO3 (111) インターフェイスにおける電子ガスの超伝導性の発見.
- LaAlO3/SrTiO3よりも大きさのオーダーである2.2ケルビンまでの超伝導的移行温度が観察されました.
- 超伝導性の二次元性は確認されました 超伝導性以前のEuO/KTaO3 (111) サンプルでは,明確なストライプ状の相が現れた.
結論:
- (111) 方向の KTaO3 インターフェースは,新興超伝導性の新しいプラットフォームを提供します.
- 観測された超伝導性は,他の酸化接点と比較して大幅に強化されています.
- ストライプフェーズの出現は,これらのインターフェースの電子フェーズの複雑な相互作用を示唆しています.
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