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

Study of quantum phase transition of two-dimensional dilute Bose gas by helium surface electrons

Research Project

Project/Area Number 16340108
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Condensed matter physics II
Research InstitutionKyoto University

Principal Investigator

ARAI Toshikazu  Kyoto University, Research Center of Low Temperature and Materials Sciences, Assistant Professor, 低温物質科学研究センター, 助手 (80333318)

Co-Investigator(Kenkyū-buntansha) YAYAMA Hideki  Kyushu University, Graduate School of Science, Associate Professor, 大学院理学研究院, 助教授 (60166840)
Project Period (FY) 2004 – 2006
Project Status Completed (Fiscal Year 2006)
Budget Amount *help
¥15,800,000 (Direct Cost: ¥15,800,000)
Fiscal Year 2006: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2005: ¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 2004: ¥7,000,000 (Direct Cost: ¥7,000,000)
Keywordsdilute Bose gas / atomic hydrogen / two-dimensional superfluidity / two-dimensional electrons / electron attachment / edgemagnetoplasmon / liquid helium / surface / 原子状水素 / 超流動 / 液面電子 / 2次元希薄気体 / 2次元 / 超流動状態 / スピン偏極 / 電気双極子
Research Abstract

Two-dimensional dilute Bose gas is expected to undergo quantum phase transitions at low temperatures. The expected low temperature phase is quasi-condensate. The reduced density matrix of quasi-condensate vanishes as a power low. In that sense, quasi-condensate does not show a true off-diagonal-long range order but it has a quasi-long range order. It is pointed out that quasi-condensate exhibits superfluidity by Kosterlitz-Thouless mechanism, in which the system is stabilized by a formation of quantized vortex pair.
With the aim of realize and observe superfluidity of two-dimensional dilute Bose gas, we cooled adsorbed two-dimensional atomic hydrogen gas on liquid helium surface. Hydrogen atoms are bounded on liquid helium surface and they lose the freedom of motion perpendicular to the surface while the motion along the surface is free. Since hydrogen atoms are Bosons, they form a two-dimensional Bose gas. Electrons, on the other hand, are also bounded on liquid helium surface and the … More system of helium surface state electrons (SSE) is a two-dimensional Coulomb gas. Since all the impurity is frozen below 1 K, the liquid helium surface is extraordinarily clean. By virtue of that, SSE exhibit very high mobility. We employed SSE as a probe to sense the state of adsorbed atomic hydrogen gas, expecting that the mobility of SSE would be ruled by collision with hydrogen atoms or excited quasiparticles.
We embedded SSE in adsorbed hydrogen gas and measured its mobility. However, unfortunately, all the measured SSE mobility showed no difference between with or without adsorbed hydrogen gas. This may be because scattering cross section of electron-hydrogen collision is too small and SSE mobility is dominated by ripplon scattering regardless of the existence of hydrogen atoms.
Although we have not yet observed two-dimensional superfluidity, we made good progresses in this research. We found that electron attachment to a hydrogen atom takes place when SSE is immersed in adsorbed atomic hydrogen and our precise measurement revealed the mechanism of the reaction. We developed pulse excited edgemagnetoplasmon technique which enabled fast SSE mobility measurement in strong magnetic fields. Recently, we found anomalous behaviors of edgemagntoplasmon signal at reduced SSE densities which cannot be explained by simple Drude model. The study of the anomalous behavior is in progress. Less

Report

(4 results)
  • 2006 Annual Research Report   Final Research Report Summary
  • 2005 Annual Research Report
  • 2004 Annual Research Report
  • Research Products

    (13 results)

All 2006 2005 Other

All Journal Article (13 results)

  • [Journal Article] Electrical conductance of single channel 1D electron system on liquid helium2006

    • Author(s)
      S.Yamanaka, T.Arai, H.Yayama
    • Journal Title

      AIP Conference Proceedings 850

      Pages: 1640-1640

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Electron Attachment Reaction Rates in 2D Atomic Hydrogen-Electron Mixed System on Liquid Helium Surface2006

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      AIP Conference Proceedings 850

      Pages: 83-83

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Electrical conductance of single channel ID electron system on liquid helium2006

    • Author(s)
      S.Yamanaka, T.Arai, H.Yayama
    • Journal Title

      AIP Conf.Proc. 850

      Pages: 1460-1460

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Electron Attachment Reaction Rates in 2D Atomic Hydrogen-Electron Mixed System on Liquid Helium Surface2006

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      AIP Conf.Proc. 850

      Pages: 83-83

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Electrical conductance of single channel 1D electron system on liquid helium2006

    • Author(s)
      S.Yamanaka, T.Arai, H.Yayama
    • Journal Title

      AIP Conf. Proc. 850

      Pages: 1460-1460

    • Related Report
      2006 Annual Research Report
  • [Journal Article] Electron Attachment Reaction Rates in 2D Atomic Hydrogen-Electron2006

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      AIP Conf. Proc. 850

      Pages: 83-83

    • Related Report
      2006 Annual Research Report
  • [Journal Article] Spin-polarization effect on electron atachment to atomic hydrogen on liquid helium surface2005

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      Journal of Low Temperature Physics 138

      Pages: 445-445

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Helium surface electron attachment to atomic hydrogen in applied magnetic field2005

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      Journal of Physics and Chemistry of Solids 66

      Pages: 1549-1549

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2006 Final Research Report Summary 2005 Annual Research Report
  • [Journal Article] Spin-polarization effect on electron attachment to atomic hydrogen on liquid helium surface2005

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      J.Low Temp.Phys. 138

      Pages: 445-445

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Helium surface electron attachment to atomic hydrogen in applied magnetic field2005

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      J.Phys.Chem.Solids 66

      Pages: 1549-1549

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2006 Final Research Report Summary
  • [Journal Article] Spin-polarization effect on electron attachment to atomic hydrogen on liquid helium surface2005

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      Journal of Low Temperature Physics 138

      Pages: 445-445

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Spin-polarization effect on electron attachment to atomic hydrogen on liquid helium surface

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      Journal of Low Temperature Physics (掲載予定)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Helium surface electron attachment to atomic hydrogen in applied magnetic field

    • Author(s)
      T.Arai, T.Mitsui, H.Yayama
    • Journal Title

      Journal of Physics and Chemistry of Solids (掲載予定)

    • Related Report
      2004 Annual Research Report

URL: 

Published: 2004-04-01   Modified: 2020-05-15  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi