Far-Infrared Cyclotron Resonance in the Inversion Layer of Silicon

Cyclotron resonance in the n-type inversion layer of silicon has been observed at 4.2^∘{}K for electron densities between (0.38 and 9.0) ×{} 10¹²/cm². The electron mass is m*=(0.20±0.01)m₀ and independent of electron density. The far-infrared mobility decreases monotonically as the electron density increases, in marked contrast to the dc mobility which exhibits a strong maximum in the same range of electron concentrations.