Fractional Quantization of the Hall Effect

Abstract

Magnetotransport of two-dimensional electrons and holes was studied in magnetic fields up to 300 kG and temperatures down to 0.5 K. In addition to previously reported structures at Landau-level filling factors $\ensuremath{\nu}=\frac{1}{3} \mathrm{and} \frac{2}{3}$, new structures were resolved at $\ensuremath{\nu}=\frac{4}{3}, \frac{5}{3}, \frac{2}{5}, \frac{3}{5}, \frac{4}{5}, \mathrm{and} \frac{2}{7}$. The results suggest that fractional quantization of the Hall effect exists in multiple series, each based on the inverse of an odd integer.