High-magnetic-field transport in a dilute two-dimensional electron gas

We report the measurement, at 0.51 K and up to 28 T, of the magnetoresistance and Hall resistance of a dilute two-dimensional electron system with 6×{}10¹⁰ cm^-2 carriers in a GaAs-GaAlAs heterojunction. The existence of an anomalous quantized Hall effect for a fractional Landau-level filling factor of 1/3 was confirmed. The magnetoresistance showed a substantial deviation from linearity above 18 T and exhibited no additional features for filling factors below 1/5 down to 1/11. The results suggest that a transition from a quantum liquid to a crystalline state may take place.