Spin transport and accumulation in the persistent photoconductor   Al$_{0.3}$Ga$_{0.7}$As
  Electrical spin transport and accumulation have been measured in highly Si doped Al0.3Ga0.7As utilizing a lateral spin transport device. Persistent photoconductivity allows for the tuning of the effective carrier density of the channel material in situ via photodoping. Hanle effect measurements are completed at various carrier densities and the measurements yield spin lifetimes on the order of nanoseconds, an order of magnitude smaller than in bulk GaAs. These measurements illustrate that this methodology can be used to obtain a detailed description of how spin lifetimes depend on carrier density in semiconductors across the metal-insulator transition. 
Jennifer Misuraca, Joon-Il Kim, Jun Lu, Kangkang Meng, Lin Chen,   Xuezhe Yu, Jianhua Zhao, Peng Xiong, and Stephan von Moln\'ar
cond-mat.mtrl-sci