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

Florida State University, Tallahassee FL

Investigators

Abstract

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.