Formation of an optical gap in the Landau-level spectrum of heavy holes in germanium

The paper presents a precise numerical calculation of the Landau levels of holes in Ge in the case when the magnetic field is parallel to the 100 direction in a wide pulse range. The spectral region corresponding to Landau levels with a negative cyclotron mass is examined, and conditions for the formation of an optical gap in the Landau-level spectrum are investigated. The results may be of interest in connection with the development of tunable long-wave radiation sources operating on transitions between valence-band Landau levels.