Electron correlation and magnetic field effect in two dimensional electron systems in semiconductors

半导体二维电子系统中的电子关联和磁场效应

• 批准号: 13304028
• 负责人: OKAMOTO Tohru
• 金额: $ 24.46万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13304028/
• 关键词: two-dimensional electron system; metal-insulator transition; electron correlation; Wigner solid; 金属・絶縁体転移

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.

我们研究了Si- mosfet， Si/SiGe异质结构和p-GaAs/AlGaAs异质结构中形成的强相关二维系统的电子和磁态。我们开发了一种用于稀释冰箱的旋转样品台。2)在Si/SiGe样品中，我们观察到即使在完全自旋极化状态下也有金属行为。我们提出了金属相在无序与内部自由度平面上的相图。3)我们发现Si-MOSFET的绝缘相中基态不是铁磁性的。4)测量了n-Si、n-GaAs和p-GaAs样品的绝缘相磁输运。结果表明，强相关体系可以观测到巨大的电阻率振荡。5)在二维空穴系统的绝缘相中观察到一个巨大的正磁阻。6)我们对Si/SiGe样品进行了回旋共振和电子自旋共振测量。

项目成果

Y.Tsuji, T.Okamoto: "Subband structure and magneto-conductivity of InAs-MIS inversion layers"Physica E. (2004年掲載予定).

Y.Tsuji、T.Okamoto：“InAs-MIS 反演层的子带结构和磁导率”Physica E.（计划于 2004 年出版）。

Y.Kawano, S.Komiyama: "Cyclotron Radiation Imaging of Nonequilibrium Electrons in Quantum Hall Devices"Recent Research Developments in Physics. 3巻. 129-153 (2002)

Y.Kawano、S.Komiyama：“量子霍尔器件中非平衡电子的回旋辐射成像”物理学最新研究进展第 3 卷。129-153 (2002)

Imaging of intra- and inter-Landau-level scattering in quantum Hall systems

量子霍尔系统中朗道能级内和朗道能级间散射的成像

• 发表时间: 2004
• 期刊: Physical Review B (Rapid Communication) 70
• 作者: Y.Kawano;T.Okamoto
• 通讯作者: T.Okamoto

Subband structure and magneto-conductivity of InAs-MIS inversion layers

InAs-MIS反型层的子带结构和磁导率

• 发表时间: 2004
• 期刊: Phisica E 22
• 作者: Y.Tsuji;T.Okamoto
• 通讯作者: T.Okamoto

S.Kawaji, H.Tanaka, H.Kawashima, T.Okamoto: "Collapse of the quantized Hall resistance : Temperature dependence"Proceedings of 25th International Conference on the Physics of Semiconductors. 969-970 (2001)

S.Kawaji、H.Tanaka、H.Kawashima、T.Okamoto：“量子化霍尔电阻的崩溃：温度依赖性”第 25 届国际半导体物理会议论文集。