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Semiconductor-baaed magneto-photonic crystals and their applications

半导体磁光子晶体及其应用

基本信息

批准号：
14205003
负责人：
TANAKA Masaaki
金额：
$ 32.61万
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：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

We have successfully grown a new quaternary alloy magnetic semiconductor (InGaMn)As, and have found that it is ferromagnetic with T_c〜130K. In (InGaMn)As, the lattice constant and the bandgap can be changed, and it can be grown on lattice-matched InP substrates, thus having good compatibility with optical communication devices. More recently, we have realized high T_c of 172-250K in Mn-delta-doped GaAs/p-AlGaAs heterostructures, which are the highest values ever reported in III-V based materials. Recently, we find out the giant planar Hall effect in Mn-delta-doped GaAs/p-AlGaAs heterostructures and clarified the magnetic anisotropy. Such new magnetic quantum heterostructures are very attractive in view of fundamental research as well as potential applications to "spintronics".Recently, we observed negative TMR and oscillations of the TMR ratio (with varying the AlAs thickness) in GaMnAs/AlAs/InGaAs/AlAs/GaMnAs double-barrier ferromagnetic tunnel junctions, for the first time in magneti … More c semiconductor systems. This is caused by the appearance of resonant tunneling and TMR effects at the same time. Realization of such large spin-dependent tunneling in semiconductor heterostructures, that is spin injection from one semiconductor layer to another semiconductor layer via tunneling, is an very significant step towards future spintronics, in which one tries to use the spin degree of freedom in semiconductor devices.We have fabricated ferromagnet(MnAs)/III-V semiconductor(GaAs) granular structures, hereafter GaAs : MnAs, by annealing (GaMn)As at 500-800℃. During the annealing process, MnAs ferromagnetic clusters with diameters of a few nm were formed in a matrix of GaAs (or GaMnAs), exhibiting a superparamagnetic behavior. We have established the fabrication process and have measured magneto-optic properties. Furthermore, we have fabricated GaAs:MnAs sandwiched by GaAs/AlAs distributed Bragg Reflectors (DBRs), and have showed significant enhancement of magneto-optical effect by using multiple interference and localization of light in the GaAs:MnAs magnetic layer. This structure offers new opportunity for the application to spin-controlled photonic devices based on III-V compound semiconductors. Recently, we have found extremely large positive magnetoresistance of 600 % at room temperature in the GaAs:MnAs granular structures, and further investigations are underway. Less

我们成功地生长了一种新的四元合金磁性半导体(InGaMn)As，并发现它具有T_c~130K的铁磁性。在(InGaMn)As中，晶格常数和带隙可以改变，并且可以在晶格匹配的InP衬底上生长，因此与光通信器件具有良好的兼容性。最近，我们在掺锰三角掺杂的GaAs/p-AlGaAs异质结中实现了172-250K的高T_c，这是III-V基材料中报道的最高T_c。最近，我们发现了掺Mn三角掺杂的GaAsp-AlGaAs异质结中的巨型平面霍尔效应，并阐明了磁各向异性。最近，我们在Magneti…中首次观察到GaMnAs/AlAs/InGaAs/AlAs/GaMnAs双势垒铁磁隧道结的TMR负值和TMR比(随AlAs厚度的变化)的振荡更多的c半导体系统。这是由于共振隧穿效应和TMR效应同时出现所致。在半导体异质结中实现如此大的自旋相关隧穿，即通过隧穿从一个半导体层到另一个半导体层的自旋注入，是迈向未来自旋电子学的重要一步，人们试图在半导体器件中利用自旋自由度。我们已经通过500-800℃的退火(GaMn)制备了铁磁/III-V半导体颗粒结构。在退火过程中，在GaAs(或GaMnAs)的基质中形成了直径为几nm的MNAs铁磁性团簇，表现出超顺磁性行为。我们已经确定了制备工艺，并测量了磁光性能。此外，我们还制作了夹在GaAs/AlAs分布布拉格反射器(DBR)中的GaAsMNAs，并通过在GaAsMNAs磁层中利用光的多次干涉和局域化显著地增强了磁光效应。这种结构为应用于基于III-V化合物半导体的自旋控制光子器件提供了新的机会。最近，我们在GaAs：MNAs颗粒结构中发现了非常大的室温下600%的正磁电阻，进一步的研究正在进行中。较少