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Time development of quantum systems and field theory

Research Project

Project/Area Number 14540280
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 素粒子・核・宇宙線
Research InstitutionWaseda University

Principal Investigator

NAKAZATO Hiromichi  Waseda University, Faculty of Science and Engineering, Professor, 理工学術院, 教授 (00180266)

Co-Investigator(Kenkyū-buntansha) YUASA Kazuya  Waseda University, Faculty of Science and Engineering, Research Assistant, 理工学術院, 助手 (90339721)
Project Period (FY) 2002 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥700,000 (Direct Cost: ¥700,000)
Keywordstime evolution of quantum systems / purification of quantum states / suppression of de coherence / Lindblad-type master equation / 量子ゼノン効果
Research Abstract

In this research project, the temporal evolution of quantum systems, especially that under the influence of the action of quantum measurements, has mainly been investigated.
As is well known, the temporal behavior of a quantum system is classified into three characteristic stages, i.e., the quadratic (Gaussian) behavior at short times, the exponential decay at intermediate times and the power decay at long times and on the basis of a solvable model, we first demonstrated these characteristics analytically.
Next, we have proposed a new scheme of driving a quantum system under investigation to a pure state irrespectively of its initial (in general mixed) state, by means of repeated measurements of another quantum system in interaction with the former. A remarkable feature of this method is that the two important notions in this kind of research work, that is, the fidelity and the yield, can be made compatible, the condition which is not easily implemented in many other attempts. Moreover, since its fundamental idea is so simple and general, it retains high flexibility and applicability and in fact, it has been generalized and applied to many different physical situations. Among such applications, purification of qubit systems, extraction of entangled states that can be spatially separated, construction of filters for more general quantum states with the help of dynamical quantum Zeno effects and an experimental proposal of this scheme in the quantum dot system are noted.
We have also investigated the master equation that usually describes a quantum system under the influence of its dissipative and decohering environment to clarify its mathematically subtle points so far somehow overlooked.

Report

(5 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • 2002 Annual Research Report
  • Research Products

    (34 results)

All 2005 2004 2003 Other

All Journal Article (30 results) Publications (4 results)

  • [Journal Article] Quantum entanglement formation by repeated spin blockade measurements in a spin field-effect transistor structure embedded with quantum dots2005

    • Author(s)
      K.Yoh, K.Yuasa, H.Nakazato
    • Journal Title

      Physica E 29・3-4

      Pages: 674-678

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] A simple schem to entangle distant qubits from a mixed state via an entanglement mediator2005

    • Author(s)
      K.Yuasa, H.Nakazato
    • Journal Title

      Progress of Theoretical Physics 114・3

      Pages: 523-531

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Governing survival probability to distill quantum states2005

    • Author(s)
      B.Militello, A.Messina, H.Nakazato
    • Journal Title

      Optics and Spectroscopy 99・3

      Pages: 438-442

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Steering distillation processes through quantum Zeno dynamics2005

    • Author(s)
      B.Militello, H.Nakazato, A.Messina
    • Journal Title

      Physical Review A 71・3

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Control of decoherence : Analysis and comparison of three different strategies2005

    • Author(s)
      P.Facchi, S.Tasaki, S.Pascazio, H.Nakazato, A.Tokuse, D.A.Lidar
    • Journal Title

      Physical Review A 71・2

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Quantum entanglement formation by repeated spin blockade measurements in a spin field-effect transistor structure embedded with quantum dots2005

    • Author(s)
      K.Yoh, K.Yuasa, H.Nakazato
    • Journal Title

      Physica E 29/3-4

      Pages: 674-678

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Annual Research Report 2005 Final Research Report Summary
  • [Journal Article] A simple scheme to entangle distant qubits from a mixed state via an entanglement mediator2005

    • Author(s)
      K.Yuasa, H.Nakazato
    • Journal Title

      Progress of Theoretical Physics 114/3

      Pages: 523-531

    • NAID

      110001840762

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Annual Research Report 2005 Final Research Report Summary
  • [Journal Article] Governing survival probability to distill quantum states2005

    • Author(s)
      B.Militello, A.Messina, H.Nakazato
    • Journal Title

      Optics and Spectroscopy 99/3

      Pages: 438-442

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Annual Research Report 2005 Final Research Report Summary
  • [Journal Article] Steering distillation processes through quantum Zeno dynamics2005

    • Author(s)
      B.Militello, H.Nakazato, A.Messina
    • Journal Title

      Physical Review A 71/3

      Pages: 32102-32102

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Control of decoherence : Analysis, comparison of three different strateeies2005

    • Author(s)
      P.Facchi, S.Tasaki, S.Pascazio, H.Nakazato, A.Tokuse, D.A.Lidar
    • Journal Title

      Physical Review A 71/2

      Pages: 22302-22302

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Steering distillation processes through quantum Zeno dynamics2005

    • Author(s)
      B.Militello, H.Nakazato, A.Messina
    • Journal Title

      Physical Review A 71;2

      Pages: 7-7

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Control of decoherence : Analysis and comparison of three different strategies2005

    • Author(s)
      P.Facchi, et al.
    • Journal Title

      Physical Review A 71;2

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Distillation of entanglement between distant system by repeated measurements on entanglement mediator2004

    • Author(s)
      G.Compagno, A.Messina, H.Nakazato, A.Napoli, M.Unoki, K.Yuasa
    • Journal Title

      Physical Review A 70・5

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Preparation and entanglement purification of qubits through Zeno-like measurements2004

    • Author(s)
      H.Nakazato, K.Yuasa, M.Unoki
    • Journal Title

      Physical Review A 70・1

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Entanglement purification through Zeno-like measurements2004

    • Author(s)
      K.Yuasa, H.Nakazato, M.Unoki
    • Journal Title

      Journal of Modern Optics 51・6-7

      Pages: 1005-1009

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Distillation of entanglement between distant systems by repeated measurements on entanglement mediator2004

    • Author(s)
      G.Compagno, A.Messina, H.Nakazato, A.Napoli, M.Unoki, K.Yuasa
    • Journal Title

      Physical Review A 70/5

      Pages: 52316-52316

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Preparation and entanglement purification of qubits through Zeno-like measurements2004

    • Author(s)
      H.Nakazato, K.Yuasa, M.Unoki
    • Journal Title

      Physical Review A 70/1

      Pages: 12303-12303

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Entanglement purification through Zeno-like measurements2004

    • Author(s)
      K.Yuasa, H.Nakazato, M.Unoki
    • Journal Title

      Journal of Modern Optics 51/6-7

      Pages: 1005-1009

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Distillation of entanglement between distant systems by repeated measurements on entanglement mediator2004

    • Author(s)
      Nakazato, A.Napoli, M.Unoki, K.Yuasa
    • Journal Title

      Physical Review A 70;5

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Preparation and entanglement purification of qubits through Zeno-like measurements2004

    • Author(s)
      H.Nakazato, K.Yuasa, M.Unoki
    • Journal Title

      Physical Review A 70;1

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Entanglement purification through Zeno-like measurements2004

    • Author(s)
      K.Yuasa, H.Nakazato, M.Unoki
    • Journal Title

      J.Mod.Opt.(Taylor & Francis) 51;6-7

      Pages: 1005-1009

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Purification of quantum state through Zeno-like measurements2003

    • Author(s)
      H.Nakazato, K.Yuasa, T.Takazawa
    • Journal Title

      Journal of Physical Society of Japan 72・C

      Pages: 34-37

    • NAID

      110002211218

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Proceedings of Waseda International Symposium on Fundamental Physics --New Perspectives in Quantum Physics--2003

    • Author(s)
      I.Ohba, Y.Aizawa, T.Daishido, S.Kurihara, K.-I.Maeda, H.Nakazato, S.Tasaki, K.Yuasa ed.
    • Journal Title

      Journal of Physical Society of Japan 72・C

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Optimization of a neutron-spin test of the quantum Zeno effect2003

    • Author(s)
      P.Facchi, Y.Nakaguro, H.Nakazato, S.Pascazio, M.Unoki, K.Yuasa
    • Journal Title

      Physical Review A 68・1

      Pages: 12107-12107

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] To decay or not to decay? Temporal behavior of a quantum system --Analysis based on a solvable model--2003

    • Author(s)
      H.Nakazato
    • Journal Title

      Fundamental Aspects of Quantum Physics

      Pages: 267-283

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Purification through Zeno-like measurements2003

    • Author(s)
      H.Nakazato, T.Takazawa, K.Yuasa
    • Journal Title

      Physical Review Letters 90・6

      Pages: 60401-60401

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Purification of quantum state through Zeno-like measurements2003

    • Author(s)
      H.Nakazato, K.Yuasa, T.Takazawa
    • Journal Title

      Journal of Physical Society of Japan(Supplement C) 72

      Pages: 34-37

    • NAID

      110002211218

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Proceedings of Waseda International Symposium on Fundamental Physics --New Perspectives in Quantum Physics--2003

    • Author(s)
      I.Ohba, Y.Aizawa, T.Daishido, S.Kurihara, K.-I.Maeda, H.Nakazato, S.Tasaki, K.Yuasa ed.
    • Journal Title

      Journal of Physical Society of Japan(Supplement C) 72

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Optimization of a neutron-spin test of the quantum Zeno effect2003

    • Author(s)
      P.Facchi, Y.Nakaguro, H.Nakazato, S.Pascazio, M.Unoki, K.Yuasa
    • Journal Title

      Physical Review A 68/1

      Pages: 12107-12107

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Purification through Zeno-like measurements2003

    • Author(s)
      H.Nakazato, T.Takazawa, K.Yuasa
    • Journal Title

      Physical Review Letters 90/6

      Pages: 60401-60401

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Publications] P.Facchi et al.: "Optimization of a neutron--spin test of the quantum Zeno effect"Physical Review A. Vol.68, No.1. 012107 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] K.Yuasa, H.Nakazato, T.Takazawa: "Purification of quantum state through Zeno-like measurements"J.Phys.Soc.Jpn.Suppl.C. Vol.72. 34-37 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] I.Ohba et al.(Editors): "Proceedings of Waseda International Symposium on Fundamental Physics ---New Perspectives in Quantum Physics---"The Physical Society of Japan. 200 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Nakazato., T.Takazawa, K.Yuasa: "Purification through Zeno-like measurements"Physical Review Letters. Vol.90. No. 6. 060401 (2003)

    • Related Report
      2002 Annual Research Report

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Published: 2002-04-01   Modified: 2016-04-21  

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