SPECTROSCOPIC STUDY OF QUANTIZED BREAKDOWN VOLTAGE STATES OF THE QUANTUM HALL-EFFECT

Quantized breakdown voltage states are observed in a second, wide, hig h-quality GaAs/AlGaAs sample made from another wafer, demonstrating th at quantization of the longitudinal voltage drop along the sample is a general feature of the quantum Hall effect in the breakdown regime. T he voltage states are interpreted in a simple energy conservation mode l as occurring when electrons are excited to higher Landau levels and then return to the original level. A spectroscopic study of these diss ipative voltage states reveals how well they are quantized. The statis tical variations of the quantized voltages increase linearly with quan tum number.