Magnetism and metal-insulator transition in two-dimensional electron systems formed in semiconductor interfaces

半导体界面中形成的二维电子系统中的磁性和金属-绝缘体转变

• 批准号: 10203210
• 负责人: OKAMOTO Tohru
• 金额: $ 5.95万
• 依托单位: University of Tokyo (2000-2001)Gakushuin University (1998-1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10203210/
• 关键词: two-dimensional electron systems; metal-insulator transition; electron correlation; Wigner solid; magnetoresistance

We have studied electronic states and magnetic states in strongly correlated two-dimensional electron systems formed in Si-MOSFETs and Si/SiGe heterostructures.1) We have measured the spin susceptibility as a function of the correlation parameter rs. The spin susceptibility monotonically increases with rs.2) We found that the magnetoresistance in parallel magnetic fields is mainly caused by the spin polarization.3) We observed the metallic phase even in the completely spin polarized system for a Si/SiGe heterostructure sample.4) We have observed oscillations of the diagonal resistivity associated with the concentration of electrons having an up-spin.5) We have established the process of making field-effect-transistor samples.6) For comparison, we have investigated on the insulating phase in two-dimensional electron systems formed in GaAs/AlGaAs field-effect-transistor device, where the electron correlations are much weaker those in the silicon systems.

我们已经研究了在Si-MoSFET和SI/SIGE异质结构中形成的密切相关的二维电子系统中的电子状态和磁状态。1）我们已经测量了自旋敏感性作为相关参数RS的函数。旋转易感性在单调上以R.2）的形式增加，我们发现，平行磁场中的磁化物主要是由自旋极化引起的。3）我们观察到金属相，即使在完全自旋的偏振系统中，对于Si/Sige异质结构样本，我们已经观察到了与对角质的振荡相关的浓度，而我们已经在浓度上建立了电子的浓度。 6）为了进行比较，我们已经研究了在GAAS/ALGAAS野外效应 - 透射器件中形成的二维电子系统中的绝缘阶段，其中电子相关性在硅系统中的电子相关性要弱得多。

项目成果

T.Okamoto, K.Hosoya, S.Kawaji, A.Yagi: "Spin Degree of Freedom in a Two-Dimensional Electron Liquid"Physical Review Letters. 82. 3875-3878 (1999)

T.Okamoto、K.Hosoya、S.Kawaji、A.Yagi：“二维电子液体中的自旋自由度”物理评论快报。

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. (2001年発表予定).

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（计划于 2001 年发表）。

T. Okamoto, K. Hosoya, S. Kawaji, A. Yagi, A. Yutani and Y. Shiraki: "Metal-Insulator Transition and Spin Degree of Freedom in Silicon 2D Electron Systems"Physica E. 6. 260-263 (2000)

T. Okamoto、K. Hosoya、S. Kawaji、A. Yagi、A. Yutani 和 Y. Shiraki：“硅二维电子系统中的金属-绝缘体跃迁和自旋自由度”Physica E. 6. 260-263 (2000

T.Okamoto,K.Hosoya,S.Kawaji,A.yagi,A.Yutani,Y.Shiraki: "Metal-Insulator transition and Spin Degree of Freedom in Silicon 2D Electron Systems"Physica E. 6. 260-263 (2000)

T.Okamoto,K.Hosoya,S.Kawaji,A.yagi,A.Yutani,Y.Shiraki：“硅二维电子系统中的金属-绝缘体转变和自旋自由度”Physica E. 6. 260-263 (2000

H.Iizuka,S.Kawaji,T.Okamoto: "Collapse of quantized Hall resistance and breakdown of dissipationless state in the integer quantum Hall effect : filling factor dependence"Physica E. 6. 132-135 (2000)

H.Iizuka、S.Kawaji、T.Okamoto：“整数量子霍尔效应中量子化霍尔电阻的崩溃和无耗散态的击穿：填充因子依赖性”Physica E. 6. 132-135 (2000)