平面ジョセフソン交差点におけるトポロジカル超伝導性の証拠
Antonio Fornieri1, Alexander M Whiticar1, F Setiawan2
1Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen and Microsoft Quantum Lab Copenhagen, Copenhagen, Denmark.
Nature
|April 26, 2019
まとめ
量子コンピューティングに不可欠なマイオラナゼロモードは,ジョセフソン・ジャンクションで観察されました. フェーズチューニングは 臨界磁場を減らし,フェーズチューニングの トポロジカル超伝導性を確認した.
科学分野:
- 凝縮物質物理学
- 量子コンピューティング
背景:
- マジョラーナゼロモードは,トポロジカルな超伝導体の境界にある準粒子状態であり,故障耐性量子コンピューティングに不可欠です.
- 以前の研究では,超伝導体半導体ナノワイヤのマイオラナゼロモードがゼロバイアスの導電性ピークを介して示された.
研究 の 目的:
- 平面ジョセフソン交差点を用いて二次元システムのマイオラナゼロモードを調査する.
- トポロジカル・フェーズ・トランジションとクリティカル・磁場に対する相差 (φ) の影響を調べる.
主な方法:
- ジョセフソン交差点のゼロバイアス伝導性のピークを測定するためにトンネルスペクトロスコーピーを利用しました.
- アルミニウム・インジウム・アルセニウムのヘテロ構造で製造されたジョセフソン・ジャンクション.
- 交差点の相差 (φ) を変化させ,磁場を適用した.
主要な成果:
- 観測された相依存ゼロバイアスの導電性ピーク.
- 交差点を φ ≈ π にバイアスすると, φ = 0 と比較して臨界磁場が減少することを発見した.
- フェーズと磁場依存性は,有限サイズのジョセフソン交差点におけるマジョラーナゼロモードの理論モデルと一致している.
結論:
- 段階調節トポロジカル超伝導性の実験的証拠を提供した.
- ジョセフソン・ジャンクションが マジョラナゼロモードを実現する 実行可能なプラットフォームであることを実証した.
- トポロジカル量子コンピューティングアーキテクチャのためのこれらのデバイスのスケーラビリティを強調しました.
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