Materials World Network: Investigation of Coherent Spin Transport in the Persistent Photoconductor AlGaAs Using All-Electronic Spin Injection and Detection

该奖项是根据2009年美国复苏和再投资法案(公共法律111-5)资助的。自旋相干和自旋输运是当今半导体自旋电子学和量子信息科学面临的两个核心问题。这个项目的中心目标是详细研究半导体中的电子自旋输运和自旋相干性作为其载流子浓度的函数。这项研究有望给出半导体中这些机制的精确和明确的观点，这将激发新的理论理解，并为自旋电子器件提供有用的指导。这一结果甚至可能为破译半导体中各种自旋退相干过程提供一种新的方法。材料世界网络奖支持佛罗里达州立大学和中国科学院半导体研究所的合作，这是材料世界网络与中国的第一个正式合作伙伴关系。具有铁磁/半导体结和半导体自旋输运通道的异质结将通过分子束外延生长，其结构和磁性将在IOS上表征；器件的制造和自旋检测将在FSU进行。这项研究的一个独特方面是使用具有可调载流子密度的半导体通道，这将使所有测量都可以在现场进行，并且只在一个样品中以不同的载流子浓度进行，即使是在金属-绝缘体的转变过程中也是如此。这个合资项目的一个更广泛的影响是，它将为参与其中的研究生提供半导体物理和磁学方面的凝聚态实验技术方面的丰富经验。计划中的交流项目将让学员直接接触到中国一流学院的材料研究。这项研究得到了DMR-CMP和DMR-OSP的支持。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Spin coherence and spin transport are two of the core issues facing semiconductor spintronics and quantum information science today. The central aim of this project is to examine in detail the electronic spin transport and spin coherence in a semiconductor as a function of its carrier concentration. This investigation is expected to yield a precise and definitive view of these mechanisms in semiconductors, which will inspire new theoretical understanding and provide useful guidelines for spintronics devices. The results may even provide a new approach to deciphering various spin decoherence processes in semiconductors. This Materials World Network (MWN) award supports a collaborative effort between the Florida State University (FSU) and the Institute of Semiconductors (IoS), Chinese Academy of Sciences, which is the first formal MWN partnership with China. Heterostructures with ferromagnet/semiconductor junctions and a semiconductor spin-transport channel will be grown by MBE and their structural and magnetic properties characterized at IoS; the device fabrication and spin detection measurements will be performed at FSU. A unique aspect of this research is the use of a semiconductor channel with tunable carrier densities, which will allow all the measurements to be carried out in situ and in only one sample at varying carrier concentrations, even through the metal-insulator transition. One of the broader impacts of this joint venture is that it will provide extensive experience in condensed matter experimental techniques in both semiconductor physics and magnetism to the graduate students involved. The planned exchange program will afford the trainees first-hand exposure to materials research in a premier Chinese institution.This research is supported by DMR-CMP and DMR-OSP.