We present data on mobility lifetime, τt, quantum lifetime, τq, and cyclotron resonance lifetime, τCR, of a sequence of high-mobility two-dimensional electron gases in the AlGaN/GaN system, covering a density range of ∼1−4.5×1012cm−2. We observe a large discrepancy between τq and τCR (τq∼τCR/6) and explain it as the result of density fluctuations of only a few percent. Therefore, only τCR --and not τq -- is a reliable measure of the time between electron scattering events in these specimens. The ratio τt/τCR increases with increasing density in this series of samples, but scattering over this density range remains predominantly in the large-angle scattering regime.
@article{arxiv.cond-mat/0312638,
title = {Electron Scattering in AlGaN/GaN Structures},
author = {S. Syed and M. J. Manfra and Y. J. Wang and R. J. Molnar and H. L. Stormer},
journal= {arXiv preprint arXiv:cond-mat/0312638},
year = {2009}
}