2004 Fiscal Year Final Research Report Summary
Electron correlation and magnetic field effect in two dimensional electron systems in semiconductors
| Project/Area Number |
13304028
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | The University of Tokyo |
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Principal Investigator |
OKAMOTO Tohru The University of Tokyo, Department of Physics, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (60245371)
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| Co-Investigator(Kenkyū-buntansha) |
KAWANO Yukio The University of Tokyo, Department of Physics, Graduate School of Science, Research Associate, 大学院・理学系研究科, 助手 (90334250)
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| Project Period (FY) |
2001 – 2004
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| Keywords | two-dimensional electron system / metal-insulator transition / electron correlation / Wigner solid |
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| Research Abstract |
We have studied electronic and magnetic states in strongly correlated two-dimensional systems formed in Si-MOSFETs, Si/SiGe heterostructures, and p-GaAs/AlGaAs heterostructures.
1)We have developed a rotatory sample stage used in a dilution refrigerator.
2)We observed a metallic behavior even for the completely spin polarized state in a Si/SiGe sample. We proposed a phase diagram for the condition of the metallic phase on the plane of disorder vs internal degree of freedom.
3)We found that the ground state in the insulating phase of a Si-MOSFET is not ferromagnetic.
4)Magnetotransport in the insulating phase has been measured for n-Si,n-GaAs and p-GaAs samples. The results indicate that giant resistivity oscillations can be observed for strongly correlated systems.
5)We observed a giant positive magnetoresistance in the insulating phase ofa 2D hole system.
6)We have performed cyclotron resonance and electron spin resonance measurements for a Si/SiGe sample.
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