Reports of weak local minima in the magnetoresistance at ν=2+3/5, 2+3/7, 2+4/9, 2+5/9, 2+5/7, and 2+5/8 in the second Landau level of the electron gas in GaAs/AlGaAs left open the possibility of fractional quantum Hall states at these filling factors. In a high quality sample we found that the magnetoresistance exhibits peculiar features near these filling factors of interest. These features, however, cannot be associated with fractional quantum Hall states; instead they originate from magnetoresistive fingerprints of the electronic bubble phases. We found only two exceptions: at ν=2+2/7 and 2+5/7 there is evidence for incipient fractional quantum Hall states at intermediate temperatures. As the temperature is lowered, these fractional quantum Hall states collapse due to a phase competition with bubble phases.
@article{arxiv.1806.09753,
title = {Finite Temperature Behavior in the Second Landau Level of the Two-dimensional Electron Gas},
author = {V. Shingla and E. Kleinbaum and A. Kumar and L. N. Pfeiffer and K. W. West and G. A. Csathy},
journal= {arXiv preprint arXiv:1806.09753},
year = {2018}
}