グラフェン超格子におけるトポロジカル電流の検出

R V Gorbachev¹, J C W Song², G L Yu³

¹Centre for Mesoscience and Nanotechnology, University of Manchester, Manchester M13 9PL, UK. School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.

Science (New York, N.Y.)

|October 25, 2014

まとめ

トポロジカル・マテリアルは,磁場のない独特のホール型電流を発揮する. グラフェン超格子には,長距離,電荷中立の流れが示され,新しいバレーベースの情報処理が可能です.

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
ナノテクノロジーナノテクノロジー

背景:

トポロジカルな材料は,磁場なしで横断電流を生成することができる.
逆対称性が破られたグラフェン超網は,独特の谷間依存のトポロジカル電流を宿していることが予測されています.

研究の目的:

グラフェン超格子における予測された長距離,中性電荷のトポロジカル電流を実験的に観察し,特徴づけること.
将来の電子アプリケーションのためのこれらのトポロジカル電流の可能性を調査する.

主な方法:

逆対称性が破られたグラフェン超網の製造.
ディラック点近くの磁場ゼロにおける非局所電圧の測定.
電流の強度とゲート電圧制御の特徴.

主要な成果:

磁場ゼロにおけるトポロジカル電流を示す非ローカル電圧の観測.
これらの電流を数ミクロメートルの範囲で検知し,遠距離輸送を証明した.
トポロジカルな電流は,適用された電流と強さで比較可能であることが判明し,大きなバレー・ホール角を暗示しています.

結論:

グラフェン超格子における予測されたトポロジカル電流の実験的確認.
長距離の電荷中性フローとトランジスタのような制御の実証.
グラフェンの自由度渓谷を利用して,新しい情報処理装置の開発の可能性.

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