スピン変換研究に向けた電気的超高速局所スピンプローブの開発と応用

2017 Fiscal Year Annual Research Report

• Project Area: nano spin conversion science
• Project/Area Number: 17H05187
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: 大塚 朋廣 国立研究開発法人理化学研究所, 創発物性科学研究センター, 客員研究員 (50588019)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 量子ドット / 局所スピン状態 / ナノ・マイクロデバイス

Outline of Annual Research Achievements

本研究では半導体量子ドット等の半導体ナノ構造を活用することにより、ナノ構造中の局所スピン状態にアクセスできる電気的高速局所スピンプローブを開発し、これを用いてナノ構造中の局所スピン現象を調べた。本年度は特に、電気的高速局所スピンプローブの開発、および電気的高速局所スピンプローブを用いた局所スピン状態ダイナミクスの測定を中心に行った。
スピン変換現象等をミクロで動的な観点から明らかにするためには、スピン変換デバイス等の中に生じたミクロな局所スピン状態に直接的にアクセスでき、その時間変化まで捉えることのできる高速局所スピンプローブが有用となる。このプローブを半導体量子ドットと高周波電気測定技術を用いた高速電荷状態プローブと、半導体量子ドット内のスピン・電荷変換現象を活用して実現した。半導体量子ドットの中にはスピンに依存した準位が存在し、この準位への電子のトンネルを利用して、局所スピンの状態を電荷移動の有無に変換して検出することができる。実際に半導体量子ドット中のスピン依存三重項状態を利用して、高速局所スピンプローブを開発した。
実現した高速局所スピンプローブを用いて、ナノ構造中の局所スピン状態ダイナミクスの測定を開始した。半導体量子ドットと電極からなる複合系における局所スピン状態を観測し、半導体量子ドット内のスピン状態が時間とともに変化する様子をミクロに観測した。さらにこの時間変化についてトンネル結合や、量子ドット内準位に対する依存性の詳細を測定した。

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

電気的高速局所スピンプローブを開発し、ナノ構造中の局所スピン状態ダイナミクスをミクロかつ高精度に観測することができたため。

Strategy for Future Research Activity

電気的高速局所スピンプローブを活用することにより、さまざまな系での局所スピン状態の測定とミクロなメカニズムの解明を進めていく。

Research Products

• [Int'l Joint Research] ルール大学ボーフム(ドイツ)
  • Country Name: GERMANY
  • Counterpart Institution: ルール大学ボーフム
• [Int'l Joint Research] バーゼル大学(スイス)
  • Country Name: SWITZERLAND
  • Counterpart Institution: バーゼル大学
• [Journal Article] A triangular triple quantum dot with tunable tunnel couplings (2017)
  • Author(s): Noiri A、Kawasaki K、Otsuka T、Nakajima T、Yoneda J、Amaha S、Delbecq M R、Takeda K、Allison G、Ludwig A、Wieck A D、Tarucha S
  • Journal Title: Semiconductor Science and Technology Volume: 32 Pages: 084004-1-5
  • DOI: 10.1088/1361-6641/aa7596
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Robust Single-Shot Spin Measurement with 99.5% Fidelity in a Quantum Dot Array (2017)
  • Author(s): Nakajima Takashi、Delbecq Matthieu R.、Otsuka Tomohiro、Stano Peter、Amaha Shinichi、Yoneda Jun、Noiri Akito、Kawasaki Kento、Takeda Kenta、Allison Giles、Ludwig Arne、Wieck Andreas D.、Loss Daniel、Tarucha Seigo
  • Journal Title: Physical Review Letters Volume: 119 Pages: 017701-1-6
  • DOI: 10.1103/PhysRevLett.119.017701
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Higher-order spin and charge dynamics in a quantum dot-lead hybrid system (2017)
  • Author(s): Otsuka Tomohiro、Nakajima Takashi、Delbecq Matthieu R.、Amaha Shinichi、Yoneda Jun、Takeda Kenta、Allison Giles、Stano Peter、Noiri Akito、Ito Takumi、Loss Daniel、Ludwig Arne、Wieck Andreas D.、Tarucha Seigo
  • Journal Title: Scientific Reports Volume: 7 Pages: 12201-1-7
  • DOI: 10.1038/s41598-017-12217-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cotunneling spin blockade observed in a three-terminal triple quantum dot (2017)
  • Author(s): Noiri A.、Takakura T.、Obata T.、Otsuka T.、Nakajima T.、Yoneda J.、Tarucha S.
  • Journal Title: Physical Review B Volume: 96 Pages: 155414-1-7
  • DOI: 10.1103/PhysRevB.96.155414
  • Peer Reviewed
• [Journal Article] A quantum-dot spin qubit with coherence limited by charge noise and fidelity higher than 99.9% (2017)
  • Author(s): Yoneda Jun、Takeda Kenta、Otsuka Tomohiro、Nakajima Takashi、Delbecq Matthieu R.、Allison Giles、Honda Takumu、Kodera Tetsuo、Oda Shunri、Hoshi Yusuke、Usami Noritaka、Itoh Kohei M.、Tarucha Seigo
  • Journal Title: Nature Nanotechnology Volume: 13 Pages: 102-106
  • DOI: 10.1038/s41565-017-0014-x
  • Peer Reviewed
• [Presentation] Dynamics of an open quantum system based on gated GaAs quantum dots (2018)
  • Author(s): Sen Li, Tomohiro Otsuka, Giles Allison, Akito Noiri, Jun Yoneda, Kenta Takeda, Takashi Nakajima, Arne Ludwig, Andreas D. Wieck, and Seigo Tarucha
  • Organizer: International Symposium on Dynamics in Artificial Quantum Systems
  • Int'l Joint Research
• [Presentation] Different charge and spin dynamics in a quantum dot-lead coupled system (2018)
  • Author(s): Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Peter Stano, Shinichi Amaha, Jun Yoneda, Kenta Takeda, Giles Allison, Akito Noiri, Takumi Ito, Daniel Loss, Arne Ludwig, Andreas D. Wieck, and Seigo Tarucha
  • Organizer: International Symposium on Dynamics in Artificial Quantum Systems
  • Int'l Joint Research
• [Presentation] A 99.9%-fidelity spin qubit in isotopically purified silicon with charge-noise-limited coherence (2018)
  • Author(s): Jun Yoneda, Kenta Takeda, Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Giles Allison, Takumu Honda, Tetsuo Kodera, Shunri Oda, Yusuke Hoshi, Noritaka Usami, Kohei M. Itoh, and Seigo Tarucha
  • Organizer: International Symposium on Dynamics in Artificial Quantum Systems
  • Int'l Joint Research
• [Presentation] A two-qubit entangling gate between spin qubits of different kinds (2018)
  • Author(s): Akito Noiri, Takashi Nakajima, Jun Yoneda, Matthieu R. Delbecq, Peter Stano, Tomohiro Otsuka, Kenta Takeda, Shinichi Amaha, Giles Allison, Kento Kawasaki, Arne Ludwig, Andreas D. Wieck, Daniel Loss, and Seigo Tarucha
  • Organizer: International Symposium on Dynamics in Artificial Quantum Systems
  • Int'l Joint Research
• [Presentation] Difference in charge and spin dynamics in a quantum dot-lead hybrid system (2017)
  • Author(s): Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Peter Stano, Shinichi Amaha, Jun Yoneda, Kenta Takeda, Giles Allison, Akito Noiri, Takumi Ito, Daniel Loss, Arne Ludwig, Andreas D. Wieck, Seigo Tarucha
  • Organizer: International Conference on Electronic Properties of Two Dimensional Systems
  • Int'l Joint Research
• [Presentation] Quantum non-demolition readout of a single spin in a quantum dot (2017)
  • Author(s): Akito Noiri, Takashi Nakajima, Jun Yoneda, Tomohiro Otsuka, Kenta Takeda, Matthieu R. Delbecq, Kento Kawasaki, Giles Allison, Arne Ludwig, Andreas D. Wieck, Seigo Tarucha
  • Organizer: International Conference on Electronic Properties of Two Dimensional Systems
  • Int'l Joint Research
• [Presentation] Enhancing coherence of a single electron spin with adaptive control (2017)
  • Author(s): Takashi Nakajima, Kento Kawasaki, Akito Noiri, Jun Yoneda, Peter Stano, Tomohiro Otsuka, Kenta Takeda, Matthieu R. Delbecq, Giles Allison, Arne Ludwig, Andreas D. Wieck, Daniel Loss, Seigo Tarucha
  • Organizer: International Conference on Electronic Properties of Two Dimensional Systems
  • Int'l Joint Research
• [Presentation] Four single-spin rabi oscillations in a quadruple quantum dot (2017)
  • Author(s): Takumi Ito, Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Shinichi Amaha, Jun Yoneda, Kenta Takeda, Akito Noiri, Giles Allison, Arne Ludwig, Andreas D. Wieck, Seigo Tarucha
  • Organizer: International Conference on Electronic Properties of Two Dimensional Systems
  • Int'l Joint Research
• [Presentation] Microwave induced frequency shift and its quadrature compensation for Si/SiGe spin qubits (2017)
  • Author(s): Kenta Takeda, Jun Yoneda, Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Giles Allison, Jun Kamioka, Takumu Honda, Tetsuo Kodera, Shunri Oda, Yusuke Hoshi, Noritaka Usami, Kohei M. Itoh, Seigo Tarucha
  • Organizer: International Workshop on Silicon Quantum Electronics
  • Int'l Joint Research
• [Presentation] Charge-noise-limited coherence and three-nines fidelity of an enriched Si/SiGe spin qubit (2017)
  • Author(s): Jun Yoneda, Kenta Takeda, Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Giles Allison, Takumu Honda, Tetsuo Kodera, Shunri Oda, Yusuke Hoshi, Noritaka Usami, Kohei M. Itoh, Seigo Tarucha
  • Organizer: International Workshop on Silicon Quantum Electronics
  • Int'l Joint Research
• [Presentation] A controlled-phase gate between spin qubits of different kinds (2017)
  • Author(s): Akito Noiri, Takashi Nakajima, Jun Yoneda, Matthieu R. Delbecq, Peter Stano, Tomohiro Otsuka, Kenta Takeda, Shinichi Amaha, Giles Allison, Kento Kawasaki, Arne Ludwig, Andreas D. Wieck, Daniel Loss, and Seigo Tarucha
  • Organizer: Conference and Workshop on Spin-Based Quantum Information Processing
  • Int'l Joint Research
• [Presentation] An isotopically-enriched silicon spin qubit with >99.9% fidelity and charge-noise-limited coherence (2017)
  • Author(s): Jun Yoneda, Kenta Takeda, Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Giles Allison, Takumu Honda, Tetsuo Kodera, Shunri Oda, Yusuke Hoshi, Noritaka Usami, Kohei M. Itoh, and Seigo Tarucha
  • Organizer: Conference and Workshop on Spin-Based Quantum Information Processing
  • Int'l Joint Research
• [Presentation] Probing Dynamics of Local Electronic States in Nanostructures Utilizing Fast Quantum Dot Probes (2017)
  • Author(s): Tomohiro Otsuka, Takashi Nakajima, Matthieu R. Delbecq, Shinichi Amaha, Jun Yoneda, Kenta Takeda, Giles Allison, Peter Stano, Akito Noiri, Takumi Ito, Daniel Loss, Arne Ludwig, Andreas D. Wieck, and Seigo Tarucha
  • Organizer: International Symposium on Fluctuation and Structure out of Equilibrium
  • Int'l Joint Research
• [Remarks] 研究成果報告用個人ページ
  • URL: http://ja.tomootsuka.net