Spin Control in Semiconductor Nanostructures

半导体纳米结构中的自旋控制

• 批准号: 09244105
• 负责人: KATAYAMA-YOSHIDA Hiroshi
• 金额: $ 76.29万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-09244105/
• 关键词: Semiconductor nanostructures; superstructures; spin; diluted magnetic semiconductor; Magentic ions; exciton; Exchange interaction; Carrier-induced ferromagnetism; 束縛磁気ポーラロン; 希薄磁性半導体; 強磁性微細構造; 一次元半導体磁気光学結晶; 強磁性金属; 半導体ヘテロ構造; 強磁性半導体(GaMn)As量子ヘテ

The purpose of the project is to develop the materials design and spin control method in magnetic-semiconductor nanostructures in order to control electron spin, based on theoretical studies and experimental studies. Material design group (theory group) contributes to develop a spin control method with controlling the quantum size effect, p-d hybridization, and carrier densities in the magnetic-semiconductor nanostructures based upon the theory and ab initio electronic structure calculation. Material design group (experimental and crystal growth group) contributes to find a method for controlling spin interaction with changing the quantum size, super structure, and doping. The major results are as follows.1. A new valence control method of codoping with doping Ga (or In, Al) donor and N acceptor was developed in order to fabricate a low resistivity p-type ZnO based on ab initio calculation.2. Based upon the success in the valence control of ZnO, a material design was proposed to fabric … More ate ferromagnetic Mn-doped p-type ZnO.It is shown that the anti-ferromagnetic states is more stable than the ferromagnetic ones due to the anti-ferromagnetic super-exchange interaction, if there is no mobile hoes. Upon codoping with the mobile holes, it is shown that ferromagnetic state becomes more stable than anti-ferromagnetic state due to the ferromagnetic double-exchange interaction. Chemical trends of the magnetic state in V-, Cr-, Fe-, Co-, and Ni-doped ZnO were predicted based on the ab initio calculation.3. As for diluted magnetic semiconductors, in which thermodynamic fluctuation of magnetization is important, a new calculation method for the bound magnetic polaron is developed and the effect of the fluctuation is claified.4. We have successfully grown new artificial materials, dissimilar heterostructures consisting of ferromagnetic metal (MnAs) and semiconductor (GaAs and Si), with atomically controlled layer thickness and thermodynamic stability, III-V based magnetic semiconductor (Ga, Mn)As and its quantum heterostructures, granular ferromagnetic metal (MnAs) embedded in GaAs and related magneto-photonic crystals and also we have clarified the transport, optical, and magnetic properties of these hybrid materials which can be used for a variety of spin-controlled devices. Spin-valve type magnetoresistance (MR) has been observed in MnAs : GaAs/InGaAs superlattices, where nanoscale MnAs clusters are embedded in the GaAs layer. A granular film consisting of nanoscale MnSb dots grown on GaAs substrate was found to exhibit magnetic-field sensitive current voltage characteristics. MR ratio>10000% is obtained.It was found that the GeMnTe film has the phase change properties, and the ferromagnetic state appears after crystallization, which enables us to form ferromagnetic nanostructures by crystallization with laser-beam. Less

该项目的目的是在理论研究和实验研究的基础上，发展磁性半导体纳米结构中的材料设计和自旋控制方法，以控制电子自旋。材料设计组(理论组)在理论和从头计算的基础上，致力于发展一种控制磁性半导体纳米结构中量子尺寸效应、p-d杂化和载流子密度的自旋控制方法。材料设计组(实验和晶体生长组)致力于通过改变量子尺寸、超结构和掺杂来控制自旋相互作用的方法。主要研究结果如下：1.研究成果。在从头计算的基础上，发展了一种新的价控方法，即通过掺杂Ga(或In，Al)施主和N受主来制备低阻的p型氧化锌。在成功实现氧化锌价态控制的基础上，提出了一种用于…织物的材料设计结果表明，在不存在可移动HOE的情况下，由于反铁磁超交换作用，反铁磁态比铁磁性态更稳定。与移动空穴共掺杂后，由于铁磁双交换作用，铁磁态比反铁磁态更加稳定。在从头计算的基础上，预测了V、Cr、Fe、Co和Ni掺杂的氧化锌的磁化趋势。对于磁化强度热力学涨落很重要的稀磁半导体，提出了一种新的计算束缚磁极化子的方法，并讨论了涨落的影响。我们成功地生长了新的人工材料，包括具有原子控制层厚度和热力学稳定性的铁磁性金属(MNAs)和半导体(GaAs和Si)的不同异质结构，III-V基磁性半导体(Ga，Mn)As及其量子异质结构，镶嵌在GaAs中的颗粒状铁磁金属(MNAs)和相关的磁-光子晶体，并阐明了这些杂化材料的输运、光学和磁性，这些杂化材料可以用于各种自旋控制器件。在GaAsInGaAs超晶格中观察到了自旋阀型磁电阻(MR)，其中纳米级的MNAs团簇嵌入在GaAs层中。在GaAs衬底上生长的由纳米级的MnSb点组成的颗粒膜具有磁场敏感的电流电压特性。磁阻比为&gT；10000%，发现薄膜具有相变特性，晶化后出现铁磁状态，这使得我们可以用激光晶化形成铁磁纳米结构。较少

项目成果

J.Szczytko: "Mn Impurity in (GaMn)As Epilayers"Physical Review. B. 60. 8304 (1999)

J.Szczytko：“(GaMn)As 外延层中的 Mn 杂质”物理评论。

K.Ando: "Magnetooptic Effect of Ferromagnetic Diluted Magnetic Semiconductor Gal-xMnxAs"Journal of Applied Physics. 83. 6548-6550 (1998)

K.Ando：“铁磁稀磁半导体 Gal-xMnxAs 的磁光效应”应用物理学杂志。

T.Hayashi: "New III-V Based Magnetic (GaMnAs)/Nonmagnetic (AlAs) Semiconductor Superlattices"Applied Physics Letters. 71. 1825-1827 (1997)

T.Hayashi：“新型 III-V 基磁性 (GaMnAs)/非磁性 (AlAs) 半导体超晶格”应用物理快报。

T.Hayashi, H.Shimada, H.Shimizu, and M.Tanaka: "Tuneling Spectroscopy and Magnetoresistance in (GaMn)As/AlAs/(GaMn) As Ultrathin Magnetic Semiconductor Heterostructures"Journal of Crystal Growth. 201/202. 689-692 (1999)

T.Hayashi、H.Shimada、H.Shimizu 和 M.Tanaka：“(GaMn)As/AlAs/(GaMn) As 超薄磁性半导体异质结构中的调谐光谱学和磁阻”晶体生长杂志。

H.Shimizu, T.Hayashi, T.Nishinaga and M.Tanaka: "Magnetic and Transport Properties of III-V Based Magnetic Semiconductor (GaMn) As : Growth Condition Dependence"Applied Physics Letters. 74. 398-400 (1999)

H.Shimizu、T.Hayashi、T.Nishinaga 和 M.Tanaka：“III-V 基磁性半导体 (GaMn) As 的磁性和传输特性：生长条件依赖性”应用物理快报。