Research on Quantum Memory using Superconducting Artificial Atoms

2012 Fiscal Year Final Research Report

• Project/Area Number: 22241025
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanostructural science
• Research Institution: National Institute of Informatics (2011-2012); NTT Basic Research Laboratories (2010)
• Principal Investigator: SEMBA Koichi 国立情報学研究所, 量子情報国際研究センター, 特任教授 (50393773)
• Co-Investigator(Kenkyū-buntansha): NEMOTO Kae 国立情報学研究所, 情報学プリンシプル研究系, 教授 (80370104) ; SAITO Shiro 日本電信電話 株式会社 NTT物性科学基礎研究所, 量子電子物性研究部, 主任研究員 (90393777) ; KAKUYANAGI Kousuke 日本電信電話 株式会社 NTT物性科学基礎研究所, 量子電子物性研究部, 研究主任 (40417093) ; NAKANO Hayato 日本電信電話 株式会社 NTT物性科学基礎研究所, 量子電子物性研究部, 主任研究員 (60393774) ; ZHU Xiaobo 日本電信電話 株式会社 NTT物性科学基礎研究所, 量子電子物性研究部, リサーチアソシエイト (70536226) ; KARIMOTO Shinichi 日本電信電話 株式会社 NTT物性科学基礎研究所, 量子電子物性研究部, 研究主任 (80393734) ; KASU Makoto 佐賀大学, 工学(系)研究科(研究院), 教授 (50393731)
• Co-Investigator(Renkei-kenkyūsha): MIZUOCHI Norikazu 大阪大学, 基礎工学研究科, 准教授 (00323311)
• Project Period (FY): 2010 – 2012
• Keywords: 人工原子 / 量子メモリー / ダイヤモンド / 微小共振器 / メゾスコピック系 / 超精密計測

Research Abstract

We have demonstrated strong coupling between a solid-state quantum processing unit (a superconducting artificial atom : a flux-qubit) and a dedicated quantum memory (nitrogen-vacancy (NV) centers in diamond). These results indicate that quantum information manipulated in flux qubits can be stored to and retrieved from an ensemble of NV centers. A quantum memory is an essential component for quantum communication and information processing. Our work demonstrated that diamond is a promising candidate for a future quantum memory. This is a significant step forward in the development of a quantum computer and additionally to an interface between the microwave and optical worlds. This result also demonstrated generation of entanglement between two distinct macroscopic matter i.e., the spin state of a few tens of million (attomol) NV centers and the persistent current circulating in a micro-meter sized electronic circuit, a flux-qubit. We have analysed the dynamics of the NV center ensemble and a single NV center strongly coupled with the superconducting qubit. We also investigated mathematical tools to represent these quantum states with a generalization of Wigner function as well as other quasi-distribution functions. This physical system can be applied to construct novel quantum information devices, such as memory and interface. We investigated several possibilities and showed advantages of such devices in quantum information network

Research Products

• [Journal Article] Hybrid-systems approach to fault-tolerant quantum communication (2013)
  • Author(s): A. M. Stephens, J. Huang, K.Nemoto, and W. J. Munro
  • Journal Title: Phys. Rev Volume: A87 Pages: 052333
  • Peer Reviewed
• [Journal Article] "Experimental analysis of the measurement strength dependence of superconducting qubit readout using a Josephson bifurcation readout method" (2013)
  • Author(s): K Kakuyanagi, S Kagei, R Koibuchi, S Saito, A Lupascu, K Semba and H Nakano
  • Journal Title: New J. Phys Volume: 15 Pages: 043028
  • Peer Reviewed
• [Journal Article] Coherent growth of superconducting TiN thin films by plasma enhanced molecular beam epitaxy (2012)
  • Author(s): Y. Krockenberger, S. Karimoto, H. Yamamoto, and K. Semba
  • Journal Title: J. Appl. Phys Volume: 112 Pages: 83920-1,-4
  • Peer Reviewed
• [Journal Article] Towards a complete and continuous Wigner function for an ensemble of spins or qubits (2012)
  • Author(s): D. Harland, M. J. Everitt, K. Nemoto, T. Tilma, and T. P. Spiller
  • Journal Title: Physical Review A Volume: Volume 86 Pages: 062117
  • Peer Reviewed
• [Journal Article] SU(N)-symmetric quasi-probability distribution functions (2012)
  • Author(s): T. Tilma and K. Nemoto
  • Journal Title: Journal of Physics A : Mathematical and Theoretical Volume: Volume 45 Pages: 015302
  • Peer Reviewed
• [Journal Article] 超伝導量子ビットとスピン集団のコヒーレント結合 (招待執筆) (2012)
  • Author(s): 齊藤 志郎,X. Zhu,W.J.Munro,仙場 浩一
  • Journal Title: NTT技術ジャーナル Volume: 6月号 Pages: 13-17
  • URL: http://www.ntt.co.jp/journal/1206/files/jn201206013.pdf
• [Journal Article] 「注目されるハイブリッド量子系 ― 超伝導キュービットとダイヤモンドのNV 中心―」 (2012)
  • Author(s): 仙場 浩一
  • Journal Title: パリティ Volume: Vol.28 Pages: 11-13
• [Journal Article] Semba:"Coherent coupling of a superconducting flux qubit to an electron spin ensemble in diamond" (2011)
  • Author(s): X. Zhu, S. Saito, A. Kemp, K. Kakuyanagi, S. Karimoto, H. Nakano, W. J. Munro, Y. Tokura, M. S. Everitt, K. Nemoto, M. Kasu, N. Mizuochi, and K. Semba
  • Journal Title: Nature Volume: Volume 478 Pages: 221-224
  • Peer Reviewed
• [Journal Article] Superconducting qubit as a quantum transformer routing entanglement between a microscopic quantum memory and a macroscopic resonator (2011)
  • Author(s): A. Kemp, S. Saito, W. J. Munro, K. Nemoto, and K. Semba
  • Journal Title: Physical Review B Volume: 84 Pages: 104505
  • Peer Reviewed
• [Journal Article] Ideal quantum nondemolition measurement of a flux qubit at variable bias, Phys (2011)
  • Author(s): Ying-Dan Wang, X. Zhu, and C. Bruder
  • Journal Title: Rev Volume: B83 Pages: 134504
  • Peer Reviewed
• [Journal Article] Quantum Zeno effect with a superconducting qubit (2010)
  • Author(s): Y. Matsuzaki, S. Saito, K. Kakuyanagi, and K. Semba
  • Journal Title: Physical Review Volume: B82 Pages: 180518
  • Peer Reviewed
• [Journal Article] Generation of Non-Classical Microwave Photon States in an Inductor-Capacitor Resonator Coupled to a Superconducting Flux Qubit (2010)
  • Author(s): K. Kakuyanagi, S. Kagei, S. Saito, H. Nakano, and K. Semba
  • Journal Title: Appl. Phys. Express Volume: 3 Pages: 103101
  • Peer Reviewed
• [Journal Article] Coherent operation of a gap-tunable flux qubit, Appl (2010)
  • Author(s): X. Zhu, A. Kemp, S. Saito, and K. Semba
  • Journal Title: Phys. Lett Volume: 97 Pages: 102503
  • Peer Reviewed
• [Presentation] Integrated quantum information technology (2013)
  • Author(s): Kae Nemoto
  • Organizer: JFLI meeting on quantum information and computation
  • Place of Presentation: Paris, France
  • Year and Date: 20130304-05
• [Presentation] 超伝導キュービット・ダイヤモンドNV センタハイブリッド量子系 (2013)
  • Author(s): 仙場浩一
  • Organizer: 第60回応用物理学会春季学術講演会、薄膜・表面 分科内招待講演 (招待講演)
  • Place of Presentation: 神奈川工科大学
  • Year and Date: 2013-03-27
• [Presentation] Josephson circuit QED and hybrid quantum systems (2013)
  • Author(s): Kouichi Semba
  • Organizer: Interdisciplinary Workshop on Quantum Device ～through Mathematical Structure, National Institute of Informatics (Invited talk)
  • Place of Presentation: Chiyoda-ku Tokyo, Japan
  • Year and Date: 2013-01-15
• [Presentation] Josephson circuit QED and hybrid quantum systems (2012)
  • Author(s): Kouichi Semba
  • Organizer: International Workshop on Spectral analysis of noncommutative harmonic oscillators and quantum devices, Institute of Mathematics for Industry, Faculty of Mathematics (Invited talk)
  • Place of Presentation: Kyushu University, Fukuoka, Japan
  • Year and Date: 20121126-27
• [Presentation] "1. Superconductivity and Josephson circuit QED" "2. Hybrid Quantum Systems" (2012)
  • Author(s): Kouichi Semba
  • Organizer: The 25th Workshop on Nanoscale and Mesoscopic Systems :Exotic Quantum States in Circuit QED Systems, Hogil Kim Memorial Building (Invited talk)
  • Place of Presentation: Pohang, Korea
  • Year and Date: 20121101-02
• [Presentation] Stephens, Jingjing Huang, and William Munro "Quantum communication using a resonator-ensemble interaction [ID:96] AQIS'12 (2012)
  • Author(s): Kae Nemoto
  • Organizer: 12th Asian Quantum Information Science Conference
  • Place of Presentation: Suzhou, China
  • Year and Date: 2012-08-24
• [Presentation] Coherent Coupling of a Superconducting Flux Qubit to an Electron Spin Ensemble in Diamond, Gordon Research Conference (2012)
  • Author(s): Kouichi Semba
  • Organizer: Quantum Science, Stonehill College(Invited talk)
  • Place of Presentation: Easton, MA, USA
  • Year and Date: 2012-08-13
• [Presentation] ``Coupling a superconducting flux qubit to an NV ensemble: A hybrid system's approach for quantum media conversion,'' QCMC2012 (2012)
  • Author(s): W. J. Munro, S. Saito, X. Zhu, Y. Matsuzaki, Kae Nemoto, T. Shimooka, N. Mizuochi, and K. Semba
  • Organizer: 11th International Conference on Quantum Communication, Measurement and Computing (Hot Topic Talk)
  • Place of Presentation: Vienna, Austria
  • Year and Date: 2012-07-30
• [Presentation] ``Hybrid Quantum Devices (2011)
  • Author(s): Mark Everitt
  • Organizer: NII Shonan Meeting on Hybrid Quantum Devices, Shonan Village, Japan invited talk
  • Place of Presentation: NII湘南会議, 湘南国際村センター
  • Year and Date: 2011-11-08
• [Presentation] ``A scalable NV-Diamond quantum computer,'' (2011)
  • Author(s): Simon Devitt
  • Organizer: NII Shonan Meeting on Hybrid Quantum Devices, Shonan Village, Japan (invited talk)
  • Place of Presentation: NII湘南会議, 湘南国際村センター
  • Year and Date: 2011-11-07
• [Presentation] 量子情報・量子計算,'' (2010)
  • Author(s): 根本 香絵
  • Organizer: 情報計算化学生物学会 年会(CBI Annual meeting2010) 15(invited talk)
  • Place of Presentation: 一橋記念講堂
  • Year and Date: 2010-09-15
• [Presentation] Superconducting flux qubit NV-diamond hybrid quantum system (2010)
  • Author(s): Kouichi Semba
  • Organizer: The 11th US-Japan Joint Seminar on Quantum Electronics and Laser Spectroscopy(Invited talk)
  • Place of Presentation: "Ultimate Quantum Systems of Light andMatter- Control and Applications"
  • Year and Date: 2010-04-12
• [Remarks] 受賞:応用物理学会論文賞 2011.7.8. K. Kakuyanagi, S. Kagei, S. Saito, H. Nakano, and K. Semba, Generation of Non-Classical Microwave Photon States in an Inductor-Capacitor Resonator Coupled to a Superconducting Flux Qubit, Appl. Phys. Express 査読有3 103101 (2010)
• [Remarks] 「量子メモリーの原理実験に成功 ～ ダイヤモンドと超伝導ハイブリッド系の量子状態制御に初めて成功 ～」
  • URL: http://www.ntt.co.jp/news2011/1110/111012a.html
• [Remarks]
  • URL: http://www.brl.ntt.co.jp/J/2011/10/latest_topics_201110130201.html
• [Remarks] 「ダイヤモンドと超伝導量子ビットを直接組み合わせたハイブリッド系の量子状態制御に 世界で初めて成功」
  • URL: http://www.ntt.co.jp/journal/1201/files/jn201201063.pdf
• [Remarks] 量子情報の最先端をつたえる Interview #001 仙場浩一 特任教授 国立情報学研究所
  • URL: http://www.ryosi.com/qis/201207/01/
• [Remarks] 記事: X. Zhu, et al. Nature 478, 221.224 (2011) : Spins coupled to a persistent current, Nature, News & Views 478, 195-196 (2011)
• [Remarks] 仙場 浩一, 3000万個で量子もつれ日経サイエンス 2012年1月号 p.25
• [Remarks] 根本 香絵, NII, U Osaka Observe SC Qubit in Diamond, Observations may further Quantum Memory Technology, Superconductor Week Vol.26 No.1, pp.5-6, 2012/2/13
• [Remarks] 「NTTなど、量子メモリーの原理実験に成功.「量子もつれ」振動を制御」asahi.com(朝日新聞社):2011年10月13日
• [Remarks] 「量子メモリー実証成功, NTTなど」日経産業新聞 2011年10月13日 朝刊(11面)掲載
• [Remarks] NTTなど、量子メモリーの原理実験に成功-「量子もつれ」振動を制御 日刊工業新聞2011年10月13日 朝刊(21面)掲載
  • URL: http://www.nikkan.co.jp/news/nkx0720111013eaag.html
• [Remarks] 「NTT/阪大/NII量子メモリーの原理実験に成功」, Laser Focus World: 2011/10/14 東
  • URL: http://www.lfw-japan.jp/news2011/news_20111014_03.html
• [Remarks] 「ダイヤモンドと超伝導量子ビットを直接組み合わせたハイブリッド系の量子状態制御に世界で初めて成功」 NTT 技術ジャーナルFOCUS ON THE NEWS 2012年1月号 p.63
• [Remarks] 仙場 浩一,研究者紹介NTT 技術ジャーナル2012年1月号p.64
  • URL: http://www.ntt.co.jp/journal/1201/files/jn201201063.pdf
• [Patent(Industrial Property Rights)] 量子状態制御方法 (2010)
  • Inventor(s): 角柳孝輔,アレクサンダーケンプ, 仙場浩一
  • Industrial Property Rights Holder: 日本電信電話株式会社
  • Industrial Property Number: 特願2010-205245
  • Filing Date: 2010-09-14
• [Patent(Industrial Property Rights)] 超伝導磁束量子ビット回路 (2010)
  • Inventor(s): ズーシャオボ,齊藤志郎,ケンプアレクサンダー,仙場浩一
  • Industrial Property Rights Holder: 日本電信電話株式会社
  • Industrial Property Number: 特願2010-151720
  • Filing Date: 2010-07-02