位相制御ジョセフソン結合におけるトポロジカル超伝導性
Hechen Ren1,2, Falko Pientka1,3, Sean Hart1,4
1Department of Physics, Harvard University, Cambridge, MA, USA.
Nature
|April 26, 2019
まとめ
研究者は,HgTe量子井戸のジョセフソン交差点を用いて,トポロジカル超伝導のための2Dプラットフォームを開発しました. このシステムは,量子情報処理のためのマジョラーナ結合状態の作成と操作を可能にします.
科学分野:
- 凝縮物質物理学
- 量子情報科学
背景:
- トポロジカルな超伝導体は局所的なマジョラーナ状態を境界でホストし,トポロジカルに保護された量子情報にとって不可欠です.
- 既存の1Dシステムには 微調整が必要で 拡張性がないため 代替プラットフォームの探求が進んでいます
研究 の 目的:
- 実験的に2次元 (2D) のアーキテクチャを実現する.
- トポロジカルな超伝導性のプラットフォームとして, HgTe量子井戸のジョセフソン交差点を調査する.
主な方法:
- 薄膜アルミニウムに結合されたHgTe量子井戸を使用してジョセフソン結合の製造.
- トポロジカル状態を相差と平面内磁場で調節する.
- トポロジカル状態を決定するために,交差点の端でトンネル伝導性を測定します.
主要な成果:
- 微小な超伝導状態でのゼロバイアストンネル伝導率の最小値が観測された.
- トポロジカル状態で ゼロバイアスのピークを検出しました 磁場が増加しました
- トポロジカル状態の相差の範囲は磁場とともに体系的に拡大した.
結論:
- HgTe量子井戸のジョセフソン・ジャンクションは,トポロジカルな超伝導性のための有望な2Dプラットフォームとして機能します.
- このシステムは Majorana モードの作成と操作を容易にする.
- 2Dシステムにおけるトポロジカルな超伝導相の探査を可能にします.
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