Quantized hall effect in single quantum wells of InAs

We report magnetotransport measurements, down to 0.55 K and up to 28 T, on GaSb-InAs-GaSb heterostructures. At moderate and high fields, the magnetoresistance vanishes and the Hall resistance shows plateaus at values of h ie² when i (i = 1, 2, 3, ...) magnetic levels are fully occupied. In addition, in high mobility samples, new features appear, the most prominent being a plateau at i = 5 2. The characteristics of these features are different from those observed in GaAs-GaAlAs at fractional occupation numbers, suggesting that they are likely related to the presence of holes in this system.