Theory of magnetic coupling and magnetization reversal in non-equilibrium state

非平衡态磁耦合与磁化反转理论

• 批准号: 14540333
• 负责人: INOUE Jun-ichiro
• 金额: $ 1.6万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540333/
• 关键词: Current driven magnetization switching; Spin accumulation; Ferromagnetic single electron tunneling; Spin-orbit interaction; Current driven domain wall motion; Spin current; 磁性多層膜; スピン電流; 磁化反転; 2次元電子ガス; 強磁性半導体; 磁気抵抗効果

The purpose of this project is to study the spin accumulation in magnetic nano-structure, current induced magnetization switching, and magnetic domain wall motion driven by spin polarized current in order to realize novel magnetic nano-devices. Following results have been obtained.1)It has been clarified that the spin accumulation exists in the non-equilibrium state of two-dimensional electron, gas with Rashba spin-orbit interaction by using a microscopic model.2)Role of spin accumulation in magnetic dots with double tunnel barrier has been studied and clarified that the current driven magnetization switching is possible by adjusting the size of the dots and anisotropy energy.3)Distribution of polarized spins in ferromagnet/nonmagnet/ferromagnet junctions with non-collinear magnetizations has been studied by using a generalized expression for current which includes both charge and spin degrees of freedom.4)Theoretical study on the domain wall motion driven by spin polarized current has been done. It has been shown that the spin and charge currents are important for thick and thin domain walls, respectively.

本项目的目的是研究磁性纳米结构中的自旋积累、电流诱导的磁化转变以及自旋极化电流驱动的磁畴壁运动，以实现新型的磁性纳米器件。得到以下结果：1)阐明了二维电子的非平衡态存在自旋积累，用微观模型研究了气体与Rashba自旋-轨道相互作用的微观模型。2)研究了双隧道势垒磁点中自旋积累的作用，阐明了通过调节磁点尺寸和各向异性能实现电流驱动磁化转换的可能性。3)利用电流的广义表达式研究了非共线磁化的铁磁/非磁/铁磁结中极化自旋的分布。4)对自旋极化电流驱动的磁化壁运动进行了理论研究。结果表明，自旋电流和电荷电流分别对厚磁区和薄磁区是重要的。

项目成果

伊藤博介, 井上順一郎, A.Umerski, J.Mathon: "非磁性スペーサ層によるTMRの量子振動の理論"日本応用磁気学会誌. (印刷中). (2003)

Hirosuke Ito、Junichiro Inoue、A.Umerski、J.Mathon：“使用非磁性间隔层的 TMR 量子振荡理论”日本应用磁学学会杂志（2003 年出版）。

J.Inoue, G.E.W.Bauer, L.W.Molemkamp: "Diffuse transport and spin accumulation in a Rashba two-dimensional electron gas"Physical Review B. 67. 33104-33107 (2003)

J.Inoue、G.E.W.Bauer、L.W.Molemkamp：“Rashba 二维电子气中的扩散传输和自旋积累”物理评论 B. 67. 33104-33107 (2003)

J.Inoue, G.E.W.Bauer, L.W.Molenkamp: "Diffuse transport and spin accumulation in a Rashba two-dimensional electron gas"Phys.Rev. B. 67. 33104-33107 (2003)

J.Inoue、G.E.W.Bauer、L.W.Molenkamp：“Rashba 二维电子气中的扩散传输和自旋积累”Phys.Rev。

J.Inoue, G.E.W.Bauer, L.W.Molenkamp: "Diffuse transport and spin accumulation in a Rashba two-dimensional gas"Phys.Rev.B. 67巻. 033104-033107 (2003)

J.Inoue、G.E.W.Bauer、L.W.Molenkamp：“Rashba 二维气体中的扩散传输和自旋积累”Phys.Rev.B. vol. 033104-033107 (2003)

J.Inoue: "Effective exchange interaction and Curie temperature in magnetic semiconductors"Phys.Rev.B. 67巻(印刷中). (2003)

J. Inoue：“磁性半导体中的有效交换相互作用和居里温度”Phys.Rev.B. 第 67 卷（出版中）。