| Project/Area Number |
05452044
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | GAKUSHUIN UNIVERSITY |
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Principal Investigator |
KAWAJI Shinji GAKUSHUIN UNIVERSITY・DEPT OF PHYSICS,PROFESSOR, 理学部, 教授 (00080440)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Tohru GAKUSHUIN UNIVERSITY・DEPT OF PHYSICS,ASSISTANT, 理学部, 助手 (60245371)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1994: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1993: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Keywords | Two-dimensional electron system / Strong magnetic field / Low temoerature / Ground state / Quantum Hall effect / Breakdown / Anderson localization / Metal-insulator transition / 電子局在 / 二次元電子系 / ランダウ準位 |
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| Research Abstract |
1. Breakdown of quantum Hall effect : Properties of breakdown of quantum Hall effect have been measured in magnetic fields up to 23 T at temperatures down to 0.5 K in specially designed Hall bars with the width between 3 and 120 mum, the current electrode width of 0.4 mm and the length of 3 mm made from five GaAs/AlGaAs heterostructure wafers with different concentrations and mobillities of electrons. Critical current in the onset of the breakdown was proportional to the sample width and 3/2 power of the magnetic flux density.
2. Ground state in low electron densities in strong magnetic fields : Electron mobility dependence of activation energy in diagonal resistance of GaAs/AlGaAs heterostructures was studies in low Landau level filling factors down to 1/9 and found some roles of electron-electron Coulomb interaction. Results of measurements of Hall resistance and diagonal resistance of Si-MOSFETs in magnetic fields up to 16 T at temperatures down to 50 mK showed that the insulating phase at low Landau level filling factors in Si-MOSFETs is produced by the Anderson localization.
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