We have applied a novel scanned probe method to directly resolve the interior structure of a GaAs/AlGaAs two-dimensional electron system in a tunneling geometry. We find that the application of a perpendicular magnetic field can induce surprising density modulations that are not static as a function of the field. Near six and four filled Landau levels, stripe-like structures emerge with a characteristic wave length ~2 microns. Present theories do not account for ordered density modulations on this length scale.
@article{arxiv.cond-mat/0205191,
title = {Direct observation of micron-scale ordered structure in a two-dimensional electron system},
author = {I. J. Maasilta and Subhasish Chakraborty and I. Kuljanishvili and S. H. Tessmer and M. R. Melloch},
journal= {arXiv preprint arXiv:cond-mat/0205191},
year = {2009}
}