The anisotropic effective mass of electrons is directly measured using time-resolved THz- pump/THz-probe techniques in a n-doped InGaAs semiconductor thin film. A microscopic theory is used to attribute this anisotropy in the THz probe transmission to the nonparabolicity of the conduction band. Self-consistent light-matter coupling is shown to contribute significantly to the THz response.
@article{arxiv.1011.3307,
title = {Anisotropic ultrafast electron dynamics induced by high-field terahertz pulses in n-doped InGaAs},
author = {F. Blanchard and D. Golde and F. H. Su and L. Razzari and G. Sharma and R. Morandotti and T. Ozaki and M. Reid and M. Kira and S. W. Koch and F. A. Hegmann},
journal= {arXiv preprint arXiv:1011.3307},
year = {2010}
}