Semiconductor-baaed magneto-photonic crystals and their applications

我们成功地生长了一种新的四元合金磁性半导体（InGaMn）As，发现它是铁磁的，T_c为130 K。在（InGaMn）As中，晶格常数和带隙可以改变，并且可以生长在晶格匹配的InP衬底上，因此与光通信器件具有良好的兼容性。最近，我们在Mn δ掺杂的GaAs/p-AlGaAs异质结中实现了172- 250 K的高温超导，这是迄今所报道的III-V族材料中的最高值。最近，我们在Mn δ掺杂GaAs/p-AlGaAs异质结中发现了巨平面霍尔效应，阐明了磁各向异性。最近，我们在GaMnAs/AlAs/InGaAs/AlAs/GaMnAs双势垒铁磁隧道结中首次观察到了负的TMR和TMR比随AlAs厚度变化的振荡现象，这在磁量子力学中是首次观察到的。 关于我们 c半导体系统。这是由于共振隧穿效应和TMR效应同时出现造成的。在半导体异质结构中实现这种大的自旋相关隧穿，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，是朝着未来自旋电子学迈出的非常重要的一步，在未来自旋电子学中，人们试图在半导体器件中使用自旋自由度。MnAs，（GaMn）As在500-800℃退火。在退火过程中，在GaAs（或GaMnAs）基体中形成直径为几nm的MnAs铁磁团簇，表现出超顺磁性行为。我们已经建立了制造工艺，并测量了磁光特性。此外，我们已经制作了GaAs/AlAs分布式布拉格反射器（DBR）夹在GaAs：MnAs，并表现出显着的磁光效应的增强，通过使用在GaAs：MnAs磁性层的多重干涉和本地化的光。这种结构为基于III-V族化合物半导体的自旋控制光子器件的应用提供了新的机会。最近，我们发现在室温下GaAs：MnAs颗粒结构中具有600%的极大正磁阻，并且进一步的研究正在进行中。少

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