• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

nano-scale real-space observation of surface two-dimensional electron system under ultra-low temperature and magnetic field

Research Project

Project/Area Number 12450020
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 表面界面物性
Research InstitutionThe University of Tokyo

Principal Investigator

HASEGAWA Yukio  Institute for Solid State Physics, The University of Tokyo, Associate Professor, 物性研究所, 助教授 (80252493)

Co-Investigator(Kenkyū-buntansha) EGUCHI Toyoaki  Institute for Solid State Physics, The University of Tokyo, Research Associate, 物性研究所, 助手 (70308196)
SAKAI Akira  Faculty of Engineering, Kyoto Univ., Professor, 工学研究科, 教授 (80143543)
KOMORI Fumio  Institute for Solid State Physics, The University of Tokyo, Associate Professor, 物性研究所, 助教授 (60170388)
Project Period (FY) 2000 – 2001
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥14,300,000 (Direct Cost: ¥14,300,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2000: ¥12,100,000 (Direct Cost: ¥12,100,000)
Keywordsscanning tunneling microscopy / electron standing waves / surface states / two-dimensional electronic states / 表面電子状態 / 2次元電子系
Research Abstract

We set up ultrahigh vacuum scanning tunneling microscope (UHV-STM) which can be operated under ultra-low temperature and high magnetic field, and confirmed that it works at 4K under a magnetic field of 11T. Using the instrument, we were successfully able to take images of standing wave pattern spreading in several hundred angstrom on Au(111) and Cu(111) surfaces.
We observed standing wave images on Pd/Au(111) and Pd/Cu(111) surfaces, trying to find a method to control and reduce electron density occupied in the surface electronic states, and found that a period of electron standing waves observed on monolayer-high Pd thin film is longer than those observed on Au(111) or Cu(111) substrate. The longer period on Pd layers indicates higher energy level of the surface states on the Pd layer, and thus lower electron density in the states than the substrates. The modification of the surface states is explained by considering a formation mechanism of the surface states, and is attributed to the fact that an energy level of the surface states is located just below the lower edge of the L gap of Pd electronic states. For the final goal of our project: characterization of surface two-dimensional electron system with STM in high spatial resolution, the above result is a first step since electron density in the surface states has to be reduced in order to observe effects of magnetic field to the 2D electron system.
We also observed some adsorbates on the Au(111) surface which show contrast variation in STM with a amount of magnetic field. They appear as a bright spot under no magnetic field, but at high magnetic field (6T) they show a donut-like contrast with a same period of oscillation with the standing waves. We are now trying to elucidate a mechanism of the contrast variation through more controlled experiments and a collaboration with a theoretical group.

Report

(3 results)
  • 2001 Annual Research Report   Final Research Report Summary
  • 2000 Annual Research Report
  • Research Products

    (9 results)

All Other

All Publications (9 results)

  • [Publications] T.Suzuki, Y, Hasegawa, et al.: "Electron standing-wave observation in the Pd overlayer on Au(111) and Cu(111) surface by STM"Physical Review. B64. 081403R1-081403R4 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] S.Kurokawa, A.Sakai, Y.Hasegawa: "STM barrier-height imaging of Shockley dislocations on a Au(111) reconstructed surface"Japanese Journal of Applied Physics. 40. 4277-4280 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Y.Hasegawa, T.Suzuki, T.Sakurai: "Modification of electron density in surface states"Surface Science. (発表予定).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T. Suzuki, Y. Hasegawa, et al: "Electron standing-wave observation in the Pd overlayer on Au(111) and Cu(111) surface by STJM"Physical Review. B64. 081403R (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] S. Kurokawa, A. Sakai, and Y. Hasegawa: "STM barrier-height imaging of Shockley dislocations on a Au(111) reconstructed surface"Japanese Journal of Applied Physics. 40. 4277-4280 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Y. Hasegawa, T. Suzuki, and T. Sakurai: "Modification of electron density in surface states"Surface Science. (to be published).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T.Suzuki, Y.Hasegawa, et al.: "Electron standing-wave observation in the Pd overlayer on Au(111) and Cu(111) surfaces by STM"Physical Review. B64. 081403R-1-081403R-4 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] S.Kurokawa, A.Sakai, Y.Hasegawa: "STM barrier-height imaging of Shockley dislooations on a Au(111) recobstructed surface"Japanese Journal of Applied Physics. 40. 4277-4280 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Y.Hasegawa, T.Suzuki, T.Sakurai: "Modification of electron density in surface states"Surface Science. (発表予定).

    • Related Report
      2001 Annual Research Report

URL: 

Published: 2000-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi