Similarities between the Landau spectra and dispersion relations in Si/Si_1-xGe_x quantum wells investigated by magnetotunneling spectroscopy

The current-voltage characteristics of Si/Si1-xGex hole resonant tunneling structures in the presence of strong magnetic fields both parallel and perpendicular to the interfaces revealed new resonances for the latter configuration due to Landau level tunneling. However, there are remarkable similarities between the spectra for the two different magnetic field directions. This can be understood in a semiclassical context, and indicates that the broadening of the Landau levels in Si/Si1-xGex hole resonant tunneling diodes is severe.