タイプII ウェイル半金属
Alexey A Soluyanov1, Dominik Gresch1, Zhijun Wang2
1Theoretische Physik and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland.
Nature
|November 27, 2015
まとめ
研究者は新しいタイプの ウェイルフェルミオンを発見しました 物質の新段階における 基本的な粒子です このタイプIIのウェイルフェルミオンは,WTe2のようなトポロジカル半金属で発見され,ローレンツ対称性が破裂したため,従来のタイプとは異なる.
科学分野:
- 凝縮物質物理学
- 高エネルギー物理学
- 量子力学
背景:
- 電子を含むフェルミオンは,ディラク,マジョラーナ,またはウェイルに分類される基本粒子です.
- マジョラーナとウェイルフェルミオンの実験的観測は,トポロジカルな超伝導体や半導体などの凝縮物質系における最近の発見まで限られていた.
研究 の 目的:
- 新しいタイプのフェルミオンの存在を提案する.
- この新しい粒子を 物質の未知の段階で特定する
- 既存の分類からこの新しいフェルミオンを区別するために
主な方法:
- 凝縮物質物理学の枠組みの中でディラック方程式を一般化する.
- 電子と穴の間の境界を分析する
- トポロジカル・セミメタルを特定し,これらの刺激を宿している.
主要な成果:
- 電子と穴の接触で発生するタイプIIフェルミオンの発見.
- このII型ヴェイルのフェルミオンはロレンツ対称性を破りますが,これは凝縮物質物理学では厳格に強制されない条件です.
- WTe2は,II型ウェイルフェルミオンをII型ウェイルポイントの周りの低エネルギー刺激として示す物質として予測される.
結論:
- WTe2のような材料のタイプIIウェイル点の存在は,トポロジカルセミメタルの新しいクラスを示しています.
- これらの材料は,点状のフェルミ表面を持つ従来のウェイル半金属と比較して独特の物理的性質を持っています.
- この発見はフェルミオン分類と 異質な量子材料における 顕微鏡の理解を広げました
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