Fractional quantum Hall effect in second subband of a 2DES C. A. Duarte, L. E. G. Armas, E. C. F. da Silva, G. M. Gusev, A. K. Bakarov, S. Wiedmann and J. C. Portal EPL, 94 3 (2011) 37010 Published online: 27 April 2011 DOI: 10.1209/0295-5075/94/37010