We have demonstrated by electroluminescence the injection of spin polarized electrons through Co/Al2O3/GaAs tunnel barrier into p-doped InAs/GaAs quantum dots embedded in a PIN GaAs light emitting diode. The spin relaxation processes in the p-doped quantum dots are characterized independently by optical measurements (time and polarization resolved photoluminescence). The measured electroluminescence circular polarization is about 15 % at low temperature in a 2T magnetic field, leading to an estimation of the electrical spin injection yield of 35%. Moreover, this electroluminescence circular polarization is stable up to 70 K.
@article{arxiv.cond-mat/0610424,
title = {Electrical spin injection into p-doped quantum dots through a tunnel barrier},
author = {L. Lombez and P. Renucci and P. Gallo and P. F. Braun and H. Carrere and P. H. Binh and X. Marie and T. Amand and B. Urbaszek and J. L. Gauffier and T. Camps and A. Arnoult and C. Fontaine and C. Deranlot and R. Mattana and H. Jaffres and J. M. George},
journal= {arXiv preprint arXiv:cond-mat/0610424},
year = {2009}
}