光电论坛第四十二期

自旋转移矩：纳米尺度的自旋电子学

主讲：朱健刚 教授

时间：2010年12月16日下午15:00

当电流通过铁磁层时，它不仅带有电荷，而且具有自旋角动量。由于自旋流可以与材料的局部磁化相交互，称这种效应为自旋转移力矩（STT）。在理论上，美国卡内基梅隆大学的Berger教授和IBM的Slonczewiki博士对该效应已曾做出预测，而其实验证明于1999年首次给出。自此，许多学者开始致力于探索STT的物理特性、材料相关性及潜在的技术应用。在这次讲座中，将会介绍STT效应的物理基础，讨论STT技术目前存在的一些重要应用潜力。特别是，将详细讲述由STT驱动的磁阻存储器（MRAM）技术，STT诱导的微波振荡器和新颖的自旋逻辑器件。最后，关于如何实现非电荷性纯自旋流的问题也将予以简单介绍。

When an electric current passes through a ferromagnetic layer, it not only carries charge, but also spin angular momentum. Such spin current can then interact with local magnetization, an effect referred to as spin transfer torque (STT). Theoretically predicted by Professor Berger of Carnegie Mellon University and Dr. Slonczewiki of IBM, the effect was experimentally demonstrated for the first time in 1999. Since then, there have been substantial amount of research effort in exploring the physical effect along with its material dependence and potential technological applications. In this talk, we will review the underlying physics of the STT effect and discuss some of its important and enabling applications to date. In specific, the talk will present detailed discussion on STT driven magnetoresistive random access memory (MRAM) technology, STT induced microwave oscillators, and novel spin logic devices. At the end, potential for achieving non-charge pure spin current will be mentioned.