Quantum oscillation of the cyclotron mass in two-dimensional electron systems in silicon

The cyclotron resonance of two-dimensional electron systems in silicon metal-oxide-semiconductor devices is investigated for high electron densities in high magnetic fields. The cyclotron mass, extracted from the resonance frequency, shows an oscillatory behavior. The periodicity of this oscillation is correlated with the Landau-level filling factor, with the dominant maxima of the cyclotron mass occurring at filling factors that are multiples of 4. A correlation of the oscillation amplitude with both the sample mobility and magnetic field is found. The results indicate that the observed mass oscillations result from impurity-mediated electron-electron interactions.