Optical orientation experiments have been performed in GaAs epilayers with photoexcitation energies in the 3 eV region yielding the photogeneration of spin-polarized electrons in the satellite L valley. We demonstrate that a significant fraction of the electron spin memory can be conserved when the electron is scattered from the L to the Γ valley following an energy relaxation of several hundreds of meV. Combining these high energy photo-excitation experiments with time-resolved photoluminescence spectroscopy of Γ valley spin-polarized photogenerated electrons allows us to deduce a typical L valley electron spin relaxation time of 200 fs, in agreement with theoretical calculations.
@article{arxiv.1207.5978,
title = {L-valley Electron Spin Dynamics in GaAs},
author = {T. Zhang and P. Barate and C. T. Nguyen and A. Balocchi and T. Amand and P. Renucci and H. Carrere and B. Urbaszek and X. Marie},
journal= {arXiv preprint arXiv:1207.5978},
year = {2015}
}