Cyclotron-resonance line width in InSb in the quantum limit

The width of the free electron cyclotron resonance in InSb has been studied as a function of resonant magnetic field, by means of laser spectrometers operating at seven different wavelengths. Comparison of the data with theories of line width in the quantum limit, shows that the nature of the field dependence is determined by the size of the parameter l/a, where l is the magnetic length and a the screening length.