自旋电子学和计算机硬件产业

1988年发现巨磁电阻（GMR）效应，是基于自旋的新电子学的开始。文章介绍观察效应的物理基础，以及这些效应和材料在信息存储上的应用。GMR硬盘（HDD）已经形成了数十亿美元的工业；其后发现的室温隧道磁电阻（TMR）效应已用于制造新关磁随机存储器（MRAM），它正在开创另一个数十亿美元的工业。自旋电子学研究的物理对象是自旋向上和自旋向下的载流子，而传统半导体电子学的对象是电荷为正和电荷为负的载流子，即空穴和电子。电子自旋特性进入半导体电子学，为新的器件创造了机会。为了成功地将电子自旋结合到半导体微电子技术中去，需要解决磁性原子自旋极化状态的控制，以及自旋极化载流子电流的有效注入、传输、控制、操纵和检测。评述了基于电子自旋的新器件原理、新材料的探索以及自旋相干态的光学操纵。

SPINTRONICS AND THE COMPUTER HARDWARE INDUSTRY

The discovery in 1988 of the giant magnetoresistive(GMR) effect is considered the beginning of the new, spin-based electronics. The physical basis for the observed effects is presented, and the initial successful applications of these phenomena and materials for information storage are reviewed. GMR read-head sensors have already created a multibillion dollar industry and magnetic random access memories using the tunneling magnetoresistive(TMR) effect will soon start another multibillion dollar industry. Spintronics is based on the up or down spin of the carriers rather than on electrons or holes as in traditional semiconductor electronics. This offers opportunities for a new generation of devices combining standard microelectronics. To successfully incorporate spins into existing semiconductor technology, one has to resolve technical issues such as efficient injection, transport, control and manipulation, and the detection of spin polarization as well as spin-polarized currents. The current state-of-the-art of spin-based devices, efforts in new materials fabrication, and optical spin coherent state manipulation are reviewed.