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Quantum field theory for macroscopic and mesoscopic systems

Research Project

Project/Area Number 08044097
Research Category

Grant-in-Aid for international Scientific Research

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

Principal Investigator

NAKAZATO Hiromichi  Waseda Univ., Dept.Phys., Assoc.Prof., 理工学部, 助教授 (00180266)

Co-Investigator(Kenkyū-buntansha) PAOLO Cea  Bari univ., Dept.Phys., Lect., 物理, 講師
SAVERIO Pascazio  Bari Univ., Dept.Phys., Lect., 物理, 講師
OHBA Ichiro  Waseda, Univ., Dept.Phys., Prof., 理工学部, 教授 (10063695)
RAUCH Helmut  オーストリア国立原子炉研究所, 教授
COSMAI Leona  イタリア国立原子核物理学研究機構(INFN)バリ研究所, 専任研究員
CEA Paolo  バリ大学, 物理, 講師
PASCAZIO Sav  バリ大学, 物理, 講師
Project Period (FY) 1996 – 1997
Project Status Completed (Fiscal Year 1997)
Budget Amount *help
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000)
Keywordsquantum mechanics / measurement problem / dissipative process / tunneling phenomena / neutron experiments
Research Abstract

The final goal of this project shall be to understand both macroscopic and mesoscopic systems quantum mechanically. We have investigated such topics that are closely connected to some fundamental issues of quantum mechanics with special attention to the physical and mathematical realization of the micro-macro transition. Here is a summary of the project.
1. We have proposed a solvable dynamical model for the quantum measurement proces and scrutinized the mechanism of emergence of the Wiener stochastic process in the weak-coupling, macroscopic limit. It is shown explicitly taht the free Hamiltonian of the detecting macroscopic system plays the role of the Wiener process, which implies that the stchasticity in this model is ascribed to a quantum mechanical origin. 2. Temporal evolution of quantum systems has been reinvestigated in general. Furthermore, the time development of a wave packet was directly calculated for a simple quantum system, and for the hydrogen system the exact expression of the transition amplitude between different energy levels was derived. In the latter case, the characteristic time scale in the short time region was evaluated and the oscillatory behavior was found to persist in the survival probability. 3. A neutron spin-flip experiment which clarifies the occurrence of the quantum Zeno effect has been proposed and examined experimentally and theoretically. 4. Nelson's version of quantum mechanics has beeb applied to a quantum mechanical particle tunmneling through a potential. The behavior of the particle is numerically simulated and the tunneling time has been estimated. We have also tried to take the possible dissipation effect on such a particle into account in this formalism to obtain more realistic tunneling time.
5. We summarized our research on the decoherence mechanism in the quantum mechanical measurement process in the book, "Decoherence and Quantum Measurements, " (Singapore, 1998).

Report

(3 results)
  • 1997 Annual Research Report   Final Research Report Summary
  • 1996 Annual Research Report
  • Research Products

    (26 results)

All Other

All Publications (26 results)

  • [Publications] R.Blasi: "Emergence of a Wiener prouss as a result of the qumtum mecuamical intesaction with a macroscopic medium" Physica A. 245・1-2. 189-211 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] H.Nakazato: "Time development of a wave packet and the time delay" Found.of Phys.27・12. 1709-1723 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] O, T.Zavialov: "On queptization of systems with actions unfounded from bulow" Thear.Math.Pjus.109・2. 1379-1387 (1996)

    • Related Report
      1997 Annual Research Report
  • [Publications] K.Imafuku: "Effects of inelastic scatlering on tcnneling time bosed on the generalezed diffusion process approach" Phys.Rev.A. 56・2. 1142-1153 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] I.Ohba: "A novel method to quautiye systems of dauped motion" Faemd.of Phys.27・12. 1725-1738 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] F.Mihokova: "Hindevd decay:gunntum Zeno effect through vectromagnetic field domination" Phys.Rev,A. 56・1. 25-32 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] S.Pascazio: "Dynamical origin of the quantim Zeno effect" Found.of Phys.27・12. 1655-1670 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.Cea: "Finite-temparrture genevalized Gaussian effeitive potential" J.Phys.G. 23・2. 135-141 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.Cea: "The lattice Schrodinger functional and the baekground field effective action" Phys.Lett.B. 392・1-2. 177-181 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.Cea: "Perturbation theory with a variational basis:the generaliged Gaussian effective potential" Phys.Rev.D. 55・8. 4967-4989 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.Cea: "Finite size analysis of the V(1) background field effective action" Phys.Lett.B. 397・3-4. 229-233 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] A.Agodi: "A lattice test of altemative interpratations of "triviality"on λφ^4/4 theary" Mod.Phys.Lett.A. 12・14. 1011-1024 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.Cea: "Generalized Gaussian effective potential:second-order thermal corrections" Mad.Phys.Lett.A. 12・15. 1077-1085 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.Cea: "Vacuum stability for Dirae fermions in three dimendions" Phys.Rev.D. 55・12. 7985-7988 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Z.Hradil: "Infinitely freguent mensurements and quantum Zeno effect" Phys.Lett.A. (to appear). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] M.Namiki: "Decoherence and Quantum Measureaneccts" World Scientifoo Pub.,Simgapore, 240 (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] H.Nakazato: "Understanding the quantum Zeno effect" Physics Letters A. 217・4,5. 203-208 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] H.Nakazato: "Quantum dephasing by chaos." Physics Letters A. 222. 130-136 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] R.Blasi: "Dissipative behavior of a quantum system interacting with a macroscopic medium" Physics Letters A. 223. 320-326 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] R.Blasi: "Emergenoe of a Wiener process as a result of the quantum mechanical interaction with a microscopic medium" Physica A. (to appear).

    • Related Report
      1996 Annual Research Report
  • [Publications] E.Watanuki: "Seesaw-type quark mass matrix and neutron electric dipole moment" Modern Physics Letters A. 11・22. 1835-1842 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] R.Blasi: "Short-time behavior of the correlation functions for the quantum Langevin equation" Physical Review A. 53・4. 2033-2037 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] N.Kono: "Decoherence and dephasing in a quantum measurement process" Physical Review A. 54・2. 1064-1086 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] Y.Hasegawa: "Geometric phase in coupled neutron interference loops" Phyical Review A. 53・4. 2486-2492 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] Z.Hradil: "Quantum phase in interferometry" Physical Review Letters. 76-23. 4295-4298 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] E.Jericha: "Performance of an improved perfect crystal neutron storage cavity" Nucl.Instrum.Methods Phys.Res.A. 379・2. 330-334 (1996)

    • Related Report
      1996 Annual Research Report

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Published: 1996-04-01   Modified: 2016-04-21  

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