1998 Fiscal Year Final Research Report Summary
Investigation of Anti-dot Superlattice in Quantum Hall State
| Project/Area Number |
09831002
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
極微細構造工学
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| Research Institution | Osaka University |
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Principal Investigator |
TAKAOKA Sadao Graduate School of Science, Osaka University, Associate Professor, 大学院・理学研究科, 助教授 (50135654)
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| Co-Investigator(Kenkyū-buntansha) |
OTO Kenichi Graduate School of Science, Osaka University, Research Associate, 大学院・理学研究科, 助手 (30263198)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Quantum Hall Effect / Fractional Quantum Hall Effect / Magneto-capacitance / Anti-dot Superlattice / Double-layr two-dimensional electron system / Far-infrared Fourier Spectroscopy / Edge State / Magnetic Electron Focusing Effect |
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| Research Abstract |
We have investigated the quantum phenomena in various type of two-dimensional electron system and obtained the following results.
1. The breakdown current of quantum Hall effect is not proportional to the sample width in relatively homogeneous samples, while the current is proportional to the width in inhomogeneous samples and the sample with anti-dot superlattice.We explain these results due to the uniform Hall electric field caused by the inhomogeneous potential or anti-dots.
2. The existence of the edge state in the fractional quantum Hall regime is confirmed and its width is determined by the magneto-capacitance measurement.The estimated width is of the order of microns, which is similar to the width in the integer quantum Hall regime.
3. We observe the distortion of Fermi surface in the two-dimensional electron system due to the parallel magnetic fields by the magnetic electron focusing effect.The electron concentration dependence of the distortion depends on the methods to change the concentration (by illumination or the gate voltage).
4. The cyclotron resonance of the double-layer two-dimensional electron system is measured is investigated by the Far-infrared Fourier magneto-spectrometer, where the magnetic field direction is changeable.The parallel magnetic field dependence of the cyclotron mass due to the distortion of Fermi surface is determined systematically.
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