Population inversion of Landau levels in the valence band of silicon in crossed electric and magnetic fields

The Landau level structure of the degenerate valence band of silicon in crossed electric and magnetic fields (B = 5 T. E = 0 to 5 kVcm -1 ) has been calculated using the complete effective mass Hmiltonian for the three valence subbands. The calculations reveal a population inversion between light hole Landau levels at cryogenic temperatures due to a strongly level-dependent scattering on optical phonons, which is caused by quantum mechanical mixing of light and heavy hole states in crossed E and B fields. The possibility of amplification of far-infrared radiation on light hole cyclotron resonance transitions is discussed.