自旋转移矩微波发生器的最优构型的理论分析及模拟

项目名称： 自旋转移矩微波发生器的最优构型的理论分析及模拟

项目编号： No.11274236

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 孙周洲

作者单位： 苏州大学

项目金额： 78万元

中文摘要： 自旋转移矩效应（Spin transfer torque，STT）驱动的微波振荡器作为新一代纳米尺度固体微波发生器件极具竞争力和拥有广泛的应用前景，因此近年来备受科研人员的广泛研究。如何选择优化的器件构型，从而降低启动的自旋极化电流，增强微波输出功率，调节微波频率范围，是一个不甚明朗的科学问题。本项目拟从基于带有自旋转移力矩的磁动力学方程出发，结合非线性科学中的极限环振荡，同步，分叉进入混沌等已有理论，理论分析和数值模拟探索找到STT振子的最优化的几何结构构型，从而在降低启动电流，增强功率输出，减少能耗，调节微波频率范围等方面实现电流对磁矩自旋的调控，从而为今后自旋转移矩微波发生器的器件实现和工业应用提供重要的理论依据。

中文关键词： 自旋转移矩；微波；倾斜极化；磁矩动力学；畴壁

英文摘要： Spin-transfer torque (STT) effect, employing spin-polarized current to manipulate the magnetization vectors of the magnetic nanostructures, has been attracting a great deal of attention and research after its prediction and verifications in about 2000s. The nano-scale microwave oscillator based on the STT effect has largely exploited recently since the new solid microwave generator will have great competitiveness and wide applications in future. However, high spin-polarized current threshold and low microwave output power are the main bottlenecks which hinder the spin-transfer oscillators (STOs) from laboratory to industy. How to optimize the configuration of the STO devices, for lowering the current threshold, enhancing the output power and easily adjusting microwave frequency, is still an unclear but important scientific problem. In this project, we plan to study these issues theoretically and numerically based on the modified magnetization dynamics equations with the STT effect terms. We plan to combine the STT induced oscillation research with the nonlinear physics theories such as limit cycle oscillation, synchronization, bifurcation into chaos etc. We plan to explore and obtain the optimized geometric configuration for the STOs, so that one can know how to select and manipulate the physical parameters to r

英文关键词： spin-transfer torque；microwave；tilted polarization；magnetization dynamics；domain wall