Study of Quantum Transport in Low Dimensional Electrons in Superperiodic Structures

超周期结构中低维电子的量子输运研究

• 批准号: 06402011
• 负责人: IYE Yasuhiro
• 金额: $ 13.31万
• 依托单位: 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: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06402011/
• 关键词: magnetoresistance; layred materials; superlattice; commensurability effect; organic conductors; graphite intercalation compounds; Weiss oscillation; magnetic modulation; 半導体ヘテロ構造; GaAs; AlGaAs; 分数量子効果; 希薄磁性半導体; グラファイト; 2次元電子系; ベクトルポテンシャル

The band theory which constitutes the basis of solid state physics, is essentially a description of the behavior of electrons in periodic potential. In this research project, we have investigated transport phenomena that originate from superperiodic structures. The materials investigated are natural and artificial layred materials including organic conductors, graphite interacalation compounds, semiconductor superlattices and metallic multilayrs. We also studied two-dimensional electron system at the interface of semiconductors with microstructured gate electrode. The superconducting magnet system purchased with this grant has been also effectively used in studies of diluted magnetic semiconductors.The followings are the main research acomplishments :By fabricating GaAs/AlGaAs heterostructures with microstructured ferromagnetic gate electrode on the surface, we have succeeded in applying spatially modulated magnatic field to two-dimensional electron gas. We predicted earlier that in a unidirectional modulation of magnetic field. the magnetoresistance shows commensurability oscillation effect. which we have experimentally verified in this research term.Angular-dependent magnetoresistance oscillation (ADMRO) is a phenomenon discovered in (BEDT-TTF)-based organic conductors. We have shown theoretically that it is a generic property of quasi-two-dimensional Fermi surface, and experimentally verified it by observing the ADMRO in graphite intercalation compounds and also in GaAs/AlGaAs superlattice.(BEDT-TTF)2KHg(SCN)4 exhibits a different type of ADMRO.We have clarified that it originates from the commensurability of open orbits on a quasi-one dimensional Fermi surface with the underlying unit cell by mapping of the resistivity dips from two-axis rotation measurement and by model calculations.

构成固态物理学基础的能带理论本质上是对周期势中电子行为的描述。在这个研究项目中，我们研究了起源于超周期结构的输运现象。所研究的材料是天然和人工层状材料，包括有机导体、石墨层间化合物、半导体超晶格和金属多层膜。我们还研究了具有微结构栅电极的半导体界面上的二维电子系统。利用该基金购买的超导磁体系统也有效地应用于稀磁半导体的研究，主要研究成果如下：通过制备GaAs/AlGaAs异质结构，在其表面形成微结构铁磁栅电极，成功地将空间调制磁场应用于二维电子气。我们之前预测过，在磁场的单向调制中。磁电阻表现出可磁化性振荡效应。角相关磁阻振荡（ADMRO）是在（BEDT-TTF）基有机导体中发现的一种现象。我们从理论上证明了这是准二维费米面的一个普遍性质，并通过观察石墨层间化合物和GaAs/AlGaAs超晶格中的ADMRO现象进行了实验验证。（BEDT-TTF）2KHg（SCN）4表现出不同类型的ADMRO。我们通过绘制两轴旋转测量的电阻率下降和模型计算，澄清了它起源于准一维费米表面上的开放轨道与底层晶胞的可公度性。

项目成果

Y.Iye: "Angula Osccllatin of Maguetoresistano in Layered Metals" Proceedings NEC Syruposicion(Elsevien). (印刷中). (1995)

Y.Iye：“层状金属中 Maguetoresistano 的 Angula Oscclatin”论文集 NEC Syruposicion（Elsevien）（出版中）。

M.Kato, A.Endo, S.Katsumoto and Y.Iye: "Two-Dimensional Electron Gas under Spatially Modulated Magnetic Field…a Test Ground for Electron-Electron Scattering in Controlled Environment" Phys.Rev.B to be Published.

M.Kato、A.Endo、S.Katsumoto 和 Y.Iye：“空间调制磁场下的二维电子气……受控环境中电子-电子散射的试验场”Phys.Rev.B 即将出版。

Y.Iye et al.: "Magueto transport in Modulated and Maguetci Field" Physica B. 227. 122-126 (1996)

Y.Iye 等人：“调制场和 Maguetci 场中的 Magueto 传输”Physica B. 227. 122-126 (1996)

S.Izawa, S.Katsumoto, A.Endo and Y.Iye: "Magnetoresistance Oscillation in Two-Dimensional Electron Gas under Modulated Vector Potential" J.Phys.Soc.Jpn.64. 706-710 (1995)

S.Izawa、S.Katsumoto、A.Endo 和 Y.Iye：“调制矢量势下二维电子气中的磁阻振荡”J.Phys.Soc.Jpn.64。

S.Izawa et al.: "Magutoresistane Oscillation in Two Dimensional Electron Gas" J.Phys.Soc.Jpn.64. 706-710 (1995)

S.Izawa 等人：“二维电子气中的磁阻振荡”J.Phys.Soc.Jpn.64。