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First-principles calculation of the spin-polarized current from transition-metal electrodes

Research Project

Project/Area Number 13640337
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 固体物性Ⅰ(光物性・半導体・誘電体)
Research InstitutionNihon University

Principal Investigator

ISHIDA Hiroshi  Nihon University, College of Humanities & Sciences, Professor, 文理学部, 教授 (60184537)

Project Period (FY) 2001 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥2,000,000 (Direct Cost: ¥2,000,000)
Keywordstunneling conductance / spintronics / nanocontact / spin-polarized current / field emission / ballistic conduction / density-functional theory / Green function / トンネル伝導 / ランダウエア公式 / 第一原理計算 / 国際研究者交流 / ドイツ
Research Abstract

The purpose of the present study was to develop a method for calculating the spin-polarized current through transition-metal tunnel junctions and the field-emission current from metal electrodes by a first-principles approach within density-functional theory. In our method, the Green function in the interface region is calculated self-consistently Using the embedding technique of Inglesfield and the linearized augmented plane wave (LAPW) basis set. The details are as follows:
1. The electronic structure of the 3-dimensional crystal in the interior of a semi-infinite electrode is determined by the full-potential LAPW method.
2. The complex band structure of a crytal corresponding to the Miller index of the electrode surface is calculated from the transfer matrix for 1-electron wave functions.
3. The embedding potential of a semi-infinite electrode is constructed from the evanescent and Bloch waves calculated in the step 2.
4. The electronic structure of the interface region between two semi-infinite electrodes is computed self-consistently within density functional theory.
5. The ballistic current flowing through the 'interface is calculated using the Landauer formula. We reformulated the formula in terms of the Green function and the imaginary part of the embedding potential. In addition, -we have derived a new formula that can treat also the tunnel current from localized surface states.
We applied the present formalism to the following systems:
1. We investigated field-emission currents from noble metal surfaces and clarified its dependence on the crystal orientation. It has turned out that the tunnel current from localized surface states can make a dominant contribution.
2. We investigated the spin-polarized tunnel current through tunnel junctions such as Cu/Co/Cu and also that through Fe/MgO/Fe, which is known as a best candidate for magnetic, random access memory (MRAM).

Report

(4 results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report
  • 2001 Annual Research Report
  • Research Products

    (17 results)

All Other

All Publications (17 results)

  • [Publications] D.Wortmann, H.Ishida, S.Blugel: "An ab initio Green-function formulation of the transfer matrix : Application to complex band structures"Physical Review B. 66. 165103-1-165103-10 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] D.Wortmann, H.Ishida, S.Blugel: "An embedded Green-function approach to the ballistic electron transport through an interface"Physical Review B. 66. 075113-1-075113-6 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Ishida, A.Liebsch: "Static and quasi-static response of Ag surfaces to a uniform electric field"Physical Review B. 66. 155413-1-155413-6 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Ohwaki, H.Ishida, A.Liebsch: "First-principles calculation of field emission from metal surfaces"Physical Review B. 68. 155422-1-155422-4 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] I.Merrick, J.E.Inglesfield, H.Ishida: "Electronic structure and surface reconstructions of adsorbed oxygen on copper(001)"Surface Science. 551. 158-170 (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Ishida, D.Wortmann, T.Ohwaki: "An embedding approach for the first-principles calculation of tunneling conductance"Physical Review B. 出版予定. (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] D.Wortmann, H.Ishida, S.Blugel: "An ab initio Green-function formulation of the transfer matrix : Application to complex band structures"Phys.Rev.B. 65. 165103(1)-165103(10) (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] D.Wortmann, H.Ishida, S.Blugel: "An embedded Green-function approach to the ballistic electron transport through an interface"Phys.Rev.B. 66. 075113(1)-075113(6) (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Ishida, A.Liebsch: "Static and quasi-static response of Ag surfaces to a uniform electric field"Phys.Rev.B. 66. 155413(1)-155413(6) (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Ohwaki, H.Ishida, A.Liebsch: "First-principles calculation of field emission from metal surfaces"Phys.Rev.B. 68. 155422(1)-155422(4) (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] I.Merrick, J.E.Inglesfield, H.Ishida: "Electronic structure and surface reconstructions of adsorbed oxygen on copper (001)"Surface Science. 551. 158-170 (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Ishida, D.Wortmann, T.Ohwaki: "An embedding approach for the first-principles calculation of tunneling conductance"Phys.Rev.B. (to be published). (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Ohwaki, H.Ishida, A.Liebsch: "First-principles calculation of field emission from metal surfaces"Physical Review B. 68巻. 155422(1)-155422(4) (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] I.Merrick, J.E.Inglesfield, H.Ishida: "Electronic structure and surface reconstruction of adsorbed oxygen on copper (001)"Surface Science. 551巻. 158-170 (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] D.Wortmann, H.Ishida, S.Blugel: "An embedded Green-function approach to the ballistic transport through an interface"Physical Review B. 66. 075113-1-075113-6 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] H.Ishida, A.Liebsch: "Static and quasistatic response of Ag surfaces to a uniform electric field"Physical Review B. 66. 155413-1-155413-6 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] D. Wortmannn, H. Ishida, S. Blugel: "An ab initio Green-function formulation of the transfer matrix : Application to complex bandstructures"Physical Review B. Vol. 65,April 15. (2002)

    • Related Report
      2001 Annual Research Report

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Published: 2001-04-01   Modified: 2020-05-15  

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