Ringlike structures in the density--magnetic-field ${\rho }_{xx}$ diagram of two-subband quantum Hall systems

Gerson J. Ferreira, Henrique J. P. Freire, J. Carlos Egues

Motivated by recent experiments [Zhang \textit{et al.}, Phys. Rev. Lett. \textbf{95}, 216801 (2005) and Ellenberger \textit{et al.}, cond-mat/0602271] reporting novel ringlike stru…