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Physics of small superconductors and its application to quantum computing devices

Research Project

Project/Area Number 14540321
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 固体物性Ⅱ(磁性・金属・低温)
Research InstitutionTohoku University

Principal Investigator

EBISAWA Hiromichi  Tohoku University, Graduate School of Information Sciences, Professor, 大学院・情報科学研究科, 教授 (90005439)

Co-Investigator(Kenkyū-buntansha) HAYASHI Masahiko  Tohoku University, Graduate School of Information Sciences, Associate Professor, 大学院・情報科学研究科, 助教授 (60301040)
IMAMURA Hiroshi  Tohoku University, Graduate School of Information Sciences, Associate Professor, 大学院・情報科学研究科, 助教授 (30323091)
Project Period (FY) 2002 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
Keywordssmall superconductor / single-electron-transistor / SQUID / Parity effect / Little-Parks oscillation / quantum bit / vortex / superconducting network / 超伝導体 / 不純物効果 / 高温超伝導体 / 界面効果 / t-Jモデル / dc-SQUID / ノイズ / RSJモデル / 超伝導 / メソスコピック系 / ナノテクノロジー / 量子計算 / スピニクス / ジョセフソン効果 / クーロンブロッケード
Research Abstract

Aiming to realize the quantum computers based on superconducting devices, we have investigated the basic physical properties of the small superconducting systems and also studied the mechanism of the manipulation and control of the quantum devices from a fundamental point of view. The followings are the results obtained by this research project:(1) We have studied the single-electron-transistor consisting of superconducting systems and clarified the nature of the quantum fluctuation of the voltage and its effects on the performance of the device. (2) Parity effects in a tiny SQUID are studied in terms parity projected grand canonical ensemble and clarified the effects of parity on the Josephson coupling energy. (3) The effects of the parity on the spin-injection and tunnel magneto-resistance in a superconductor is studied and clarified the relation between Coulomb blockade and spin accumulation. (4) Mesoscopic orbital magnetism in a superconductor-normal metal hybrid system and pointed out the enhanced fluctuations in diamagnetism due to mesoscopic effects. (5) Little-Parks effect in a one-dimensional superconductor is studied and it is found that the phase of the Little-Parks oscillation is reversed in tiny systems. (6) Physical properties and electronic properties of topological crystals are studied and, especially, found the appearance of specific node states in the Little-Parks oscillation of Moebius crystals. (7) The decoherence in a spin system coupling via RKKY interaction is studied and found that when the interaction is ferromagnetic, decoherence can be suppressed. (8) Phase transition and vortex structure in small superconducting networks are theoretically studied. (9) Vortex dynamics in a superconducting Corbino disk is theoretically studied.

Report

(3 results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report
  • Research Products

    (40 results)

All 2004 2003 Other

All Journal Article (24 results) Publications (16 results)

  • [Journal Article] Andreev reflection in ferromagnet / superconductor / ferromagnet double junction systems2004

    • Author(s)
      Taro Yamashit, Hiroshi Imamura, Saburo Takahashi, Sadamichi Maekawa
    • Journal Title

      Phys. Rev. B 67

      Pages: 94515-94515

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Andreev reflection in ferromagnet / super conductor / ferromagnet double junction systems2004

    • Author(s)
      T.Yamashita, H.Imamura, S.Takahashi, S.Maekawa
    • Journal Title

      Phys.Rev. B67

      Pages: 94515-11

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Spin relaxation and tunnel magnetoresistance of a ferromagnet / superconductor ferromagnet single-electron tunneling transistor2003

    • Author(s)
      Hiroshi Imamura, Yasuhiro Utsumi, Hiromichi Ebisawa
    • Journal Title

      Physica E 18

      Pages: 43-43

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Paramagnetism of two-dimensional quantum dots with superconducting core2003

    • Author(s)
      Takeru Suzuki, Masahiko Hayashi, Hiroshi Imamura, Hiromichi Ebisawa
    • Journal Title

      Physica E 18

      Pages: 327-327

    • NAID

      110009719072

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Heterogeneous high temperature cuprate superconductors2003

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Physica C 388-389

      Pages: 29-29

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Novel boundary effect in high temperature superconductors : superconductivity induced by pseudogap proximity effect2003

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Physica C 392-396

      Pages: 48-48

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Parity effect in a tiny SQUID2003

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Phys. Rev. B 67

      Pages: 14524-14524

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Time Evolution of an Exciton and a Photon Qubit Coupled with Other2003

    • Author(s)
      Yoshiaki RIKITAKE, Hiroshi IMAMURA, Hiromichi EBISAWA
    • Journal Title

      J. Phys. Soc. Jpn 72

      Pages: 3040-3040

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] The effect of large quantum Fluctuation on the noise of a single-electron transistor2003

    • Author(s)
      Yasuhiro Utsumi, Hiroshi Imamura, Masahiko Hayashi, Hiromichi Ebisawa
    • Journal Title

      Physica E 18

      Pages: 93-93

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Noise of a single-electron transistor in the regime of large quantum fluctuations of island charge out of equilibrium2003

    • Author(s)
      Yasuhiro Utsumi, Hiroshi Imamura, Masahiko Hayashi, Hiromichi Ebisawa
    • Journal Title

      Phys. Rev. B 67

      Pages: 35317-35317

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Andreev reflection in ferromagnet / superconductor / ferromagnet structures2003

    • Author(s)
      T.Yamashita, H.Imamura, S.Takahashi, S.Maekawa
    • Journal Title

      Physica E 18

      Pages: 52-52

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Spin relaxation and tunnel magnetoresistance of ferromagnet / superconductor / ferromagnet single-electrol tunneling transistor2003

    • Author(s)
      Hiroshi Imamura, Yasuhiro Utsumi, Hiromichi Ebisawa
    • Journal Title

      Physica E18

      Pages: 43-43

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Heterogeneous high temperature cuprate superconductors2003

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Physica C29

      Pages: 388-389

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Novel boundary effect in high temperature superconductors : superconductivity induced by pseudogap proximity effect2003

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Physica C48

      Pages: 392-396

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Parity effect in a tiny SQUID2003

    • Author(s)
      Masahiko Hayashi, Hiromichi Ebisawa
    • Journal Title

      Phys.Rev. B67

      Pages: 14524-14524

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Time Evaluation of an Exciton and a Photon Qubit Coupled with Each Other2003

    • Author(s)
      Yoshiaki RIKITAKE, Hiroshi IMAMURA, Hiromichi EBISAWA
    • Journal Title

      J.Phys.Soc.Jpn. 72

      Pages: 3040-3040

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Paramagnetism of two-dimensional quantum dots with superconducting core2003

    • Author(s)
      Takeru Suzuki, Masahiko Hayashi, Hiroshi Imamura, Hiromichi Ebisawa
    • Journal Title

      Physica E18

      Pages: 327-327

    • NAID

      110009719072

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] The effect of large quantum Fluctuation on the noise of a single-electron transistor2003

    • Author(s)
      Yasuhiro Utsumi, Hiroshi Imamura, Masahiko Hayashi, Hiromichi Ebisawa
    • Journal Title

      Physica E18

      Pages: 93-93

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Noise of a single-electron transistor in the regime of large quantum fluctuations of island charge out of equilibrium2003

    • Author(s)
      Yasuhiro Utsumi, Hiroshi Imamura, Masahiko Hayashi, Hiromichi Ebisawa
    • Journal Title

      Phys.Rev. B67

      Pages: 35317-35317

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Andreev reflection in ferromagnet / superconductor / ferromagnet structures2003

    • Author(s)
      T.Yamashita, H.Imamura, S.Takahashi, S.Maekawa
    • Journal Title

      Physica E18

      Pages: 52-52

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Vortex Structures in Mesoscopic Superconducting Network Systems geometry

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Physica C (to be published)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Vortex nucreation and annihilation in superconducting Corbino disks

    • Author(s)
      M.Hayashi, H.Evisawa, M.Kato
    • Journal Title

      Physica C (to be published)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Vortex Structures in Mesoscopic Superconducting Network Systems

    • Author(s)
      M.Hayashi, H.Ebisawa, M.Kato
    • Journal Title

      Phisica C(to be published)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Vortex nucreation and annihilation in superconducting Corbino disks

    • Author(s)
      M.Hayashi, H.Ebisawa
    • Journal Title

      Physica C(to be published)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Imamura, Y.Utsumi, H.Ebisawa: "Spin relaxation and tunnel magnetoresistance of a ferromagnet/ superconductor/ferromagnet single-electron tunneling transist"Physica E. 18. 43-44 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hayashi, H.Ebisawa: "Parity Effect in a Tiny SQUID"Phys.Rev.B. 67. 014524 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Y.Utsumi, H.Imamura, M.Hayashi, H.Ebisawa: "Noise of a single-electron transistor in the regime of large quantum fluctuations of island charge out of equilibrium"Phys.Rev.B. 67. 035317 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] M.Hayashi, H.Ebisawa: "Novel boundary effect in high temperature superconductors : superconductivity induced by pseudogap proximity effect"Physica C. 392(396). 48-52 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Y.Utsumi, H.Imamura, M.Hayashi, H.Ebisawa: "Noise of a single-electron transistor in the regime of large quantum fluctuations of island charge out of equilibrium"Physical Review B. 67. 035317 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Hayashi, H.Ebisawa: "Parity effect in a tiny SQUID"Physical Review B. 67. 014524 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Utsumi, H.Imamura, M.Hayashi, H.Ebisawa: "Charge fluctuation between even and odd states of a superconducting island"Physical Review B. 67. 024513 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Utsumi, H.Imamura, M.Hayashi, H.Ebisawa: "The effect of large quantum fluctuation on the noise of a single-electron transistor"Physica E. (印刷中). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Hayashi, H.Ebisawa: "Heterogeneous High Temperature Cuprate Superconductors"Physica (Proceedings of LT23). (出版予定). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Utsumi, H.Imamura, M.Hayashi, H.Ebisawa: "The effect of large quantum fluctuation on the noise of a single-electron transistor"Physica (Proceedings of LT23). (出版予定). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] T.Suzuki, M.Hayashi, H.Imamura, Hiromichi Ebisawa: "Superconducting Correlation in Orbital Magnetism of Quantum Dots"Physica (Proceedings of LT23). (出版予定). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] T.Suzuki, M.Hayashi, H.Imamura, Hiromichi Ebisawa: "Superconducting Correlation in Orbital Magnetism of Quantum Dots"Physica (Proceedings of LT23). (出版予定). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] T.Yamashitaa, H.Imamura, S.Takahashi, S.Maekawa: "Andreev Reflection in Ferromagnet/Superconductor/Ferromagnet Structures"Physica (Proceedings of LT23). (出版予定). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] S.Maekawa, S.Takahashi, H.Imamura: "Spin Injection into Superconductors"J. Phys. D.. 35. 2452-2456 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] H.Imamura, Y.Utsumi, H.Ebisawa: "Parity Effect and Tunnel Magnetoresistance of Ferromagnet/Superconductor/Ferromagnet Single-Electron Tunneling Transistors"Physical review B. 66. 054503 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] S.Maekawa, S.Takahashi, H.Imamura: "Chapter 4 (pp. 145-240) of the book "Spin dependent transport in magnetic nanostructures""Taylor & Francis. 145-240 (2002)

    • Related Report
      2002 Annual Research Report

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Published: 2002-04-01   Modified: 2020-05-15  

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