RECOVERY OF QUANTIZED BALLISTIC CONDUCTANCE IN A PERIODICALLY MODULATED CHANNEL

For a periodically modulated electron channel, conductance quantization characteristic of a simple quantum point contact is recovered. The value of the quantized conductance is, however, no longer a monotonically increasing function of energy. Comparison with the band structure of the corresponding infinite channel shows a direct correspondence between the index of the conductance plateau and the number of positive-velocity bands at a given energy. The results persist in the presence of an applied magnetic field and lead to a prediction of nonmonotonic steps in the integer quantum Hall resistance for such structures.