Spin coherence of electrons and its control in semiconductor quantum structures

半导体量子结构中电子的自旋相干性及其控制

• 批准号: 12305001
• 负责人: OHNO Hideo
• 金额: $ 27.75万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12305001/
• 关键词: Carrier-induced ferromagnetism; Diluted magnetic semiconductor; GaMnAs; InMnAs; Giant magnetoresistance; Molecular beam epitaxy; Tunnel magnetoresistance; Nuclear magnetic resonance; スピンコヒーレンス; 磁性半導体; キャリアスピン; 核スピン; スピン注入; 強磁性体

In this project, we carried out researches on (1) manifestation and control of spin coherence of electrons, (2) elucidation and control of interaction between electrons and nuclear spins or localized magnetic spins in semiconductor quantum structures, and (3) fabrication of novel devices which utilize spin-dependent electronic and optical properties based on the hybridization of conventional nonmagnetic semiconductor heterostructures and ferromagnetic semiconductors. During the term, we got the following results.1. We demonstrated, for the first time, the electric field control of ferromagnetism of a ferromagnetic semiconductor (In,Mn)As. Using a field effect transistor structure, we controlled the hole concentration in (In,Mn)As channel by a gate voltage so that the hole-mediated ferromagnetic interaction can be modulated.2. Using tow-temperature molecular beam epitaxy (LT-MBE), we successfully prepared zinc-blende CrSb, which does not exist in nature. We also demonstrated that the zi … More nc-blende CrSb is room-temperature ferromagnetic.3. We prepared (Ga,Mn)As/(Al,Ga)As/(Ga.Mn)As ferromagnetic semiconductor trilayer structures by LT-MBE in order to investigate spin-dependent transport properties. In such all semiconductor trilayer structures, we successfully demonstrated the giant magnetoresistance and tunnel magnetoresistance (TMR) effects, which have been widely utilized in magnetoelectronics devices made of metal-based junctions, in particular, exceeding 100% TMR has been realized in a (Ga,Mn)As/GaAs/(Ga,Mn)As tunnel junction.4. We prepared modulation doped GaAs/AlGaAs(110) quantum wells by MBE, and investigated the spin coherence time of electrons by a time-resolved Faraday rotation (TRFR) technique. We observed resonant spin amplification, which indicates that the electron spin coherence time is nearly 10 ns, and all optic unclear magnetic resonance.5. We prepared a spin Esaki diode, which consists of a p-(Ga,Mn)As/n-GaAs, and demonstrated electrical electron spin injection into a nonmagnetic semiconductor via interband spin tunneling in the structure. Less

在该项目中，我们对（1）对（1）电子N电子和核自旋的自旋相干性的表现和控制进行了研究铁磁半导体。可以调制洞中的相互作用2 （GA，MN）AS/（AL，GA）AS/（GA.MN）作为LT-MBE的铁磁半导体，以研究所有半导体三层结构中的自旋依赖性。 ，超过100％的TMR已在（GA，MN）AS/GAAS/（GA，MN）作为隧道交界处实现。4。技术。结构少

项目成果

H.Ohno: "Semiconductor spin electronics"JSAP International. No.5. 4-13 (2002)

H.Ohno：“半导体自旋电子学”JSAP International。

J.H. Zhao: "Growth and properties of (Ga,Mn)As on Si (100) substrate"Journal of Crystal Growth. Vol.237-239. pp.1349-1352 (2002)

J.H.

M. Kohda: "A Spin Esaki Diode"Jpn. J. Appl. Phys. Vol.40, Part2, No.12A. pp.L1274-L1276 (2001)

M. Kohda：“旋转 Esaki 二极管”Jpn。

H.Ohno: "Ferromagnetic semiconductors for spin electronics"Journal of Magnetism and Magnetic Materials. 242. 105-107 (2002)

H.Ohno：“用于自旋电子学的铁磁半导体”磁性和磁性材料杂志。

Y.Ohno: "Valence band barrier at (Ga,Mn)As/GaAs interfaces"Physica E. 13. 521-524 (2002)

Y.Ohno：“(Ga,Mn)As/GaAs 界面处的价带势垒”Physica E. 13. 521-524 (2002)