MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
Nature. 2009 Nov 26;462(7272):491-4. doi: 10.1038/nature08570.
The control and manipulation of the electron spin in semiconductors is central to spintronics, which aims to represent digital information using spin orientation rather than electron charge. Such spin-based technologies may have a profound impact on nanoelectronics, data storage, and logic and computer architectures. Recently it has become possible to induce and detect spin polarization in otherwise non-magnetic semiconductors (gallium arsenide and silicon) using all-electrical structures, but so far only at temperatures below 150 K and in n-type materials, which limits further development. Here we demonstrate room-temperature electrical injection of spin polarization into n-type and p-type silicon from a ferromagnetic tunnel contact, spin manipulation using the Hanle effect and the electrical detection of the induced spin accumulation. A spin splitting as large as 2.9 meV is created in n-type silicon, corresponding to an electron spin polarization of 4.6%. The extracted spin lifetime is greater than 140 ps for conduction electrons in heavily doped n-type silicon at 300 K and greater than 270 ps for holes in heavily doped p-type silicon at the same temperature. The spin diffusion length is greater than 230 nm for electrons and 310 nm for holes in the corresponding materials. These results open the way to the implementation of spin functionality in complementary silicon devices and electronic circuits operating at ambient temperature, and to the exploration of their prospects and the fundamental rules that govern their behaviour.
半导体中电子自旋的控制和操纵是自旋电子学的核心，自旋电子学旨在利用自旋方向而不是电子电荷来表示数字信息。基于自旋的技术可能会对纳米电子学、数据存储以及逻辑和计算机架构产生深远的影响。最近，已经可以使用全电结构在原本非磁性的半导体（砷化镓和硅）中诱导和检测自旋极化，但到目前为止，这种方法仅在 150 K 以下和 n 型材料中适用，这限制了进一步的发展。在这里，我们演示了从铁磁隧道结向 n 型和 p 型硅中室温电注入自旋极化，使用 Hanle 效应进行自旋操控，并通过电检测感应的自旋积累。在 n 型硅中产生了高达 2.9 meV 的自旋分裂，对应于 4.6%的电子自旋极化。在 300 K 时，对于高掺杂 n 型硅中的传导电子，提取的自旋寿命大于 140 ps，对于相同温度下的高掺杂 p 型硅中的空穴，提取的自旋寿命大于 270 ps。对于相应材料中的电子和空穴，自旋扩散长度大于 230 nm 和 310 nm。这些结果为在环境温度下运行的互补硅器件和电子电路中实现自旋功能铺平了道路，并为探索它们的前景和控制其行为的基本规则奠定了基础。
