Most of the fractions observed to date belong to the sequences ν=n/(2pn±1) and ν=1−n/(2pn±1), n and p integers, understood as the familiar {\em integral} quantum Hall effect of composite fermions. These sequences fail to accommodate, however, many fractions such as ν=4/11 and 5/13, discovered recently in ultra-high mobility samples at very low temperatures. We show that these "next generation" fractional quantum Hall states are accurately described as the {\em fractional} quantum Hall effect of composite fermions.
@article{arxiv.cond-mat/0404079,
title = {Microscopic origin of the next generation fractional quantum Hall effect},
author = {C. -C Chang and J. K. Jain},
journal= {arXiv preprint arXiv:cond-mat/0404079},
year = {2009}
}