Probing semiconductor superlattice transport by submillimeter wave cyclotron resonance

Cyclotron resonance with the magnetic field oriented perpendicular to the growth direction is shown to be an effective probe of vertical transport in semiconductor superlattices. For small magnetic fields the experiments directly measure the mini-band mass and scattering rate. At large magnetic fields, when the cyclotron diameter is comparable to the superlattice period, we have a rare opportunity to examine Landau states in a periodic potential in a magnetic field when the effective mass approximation is no longer applicable. Under these conditions we can resolve resonances from different parts of the superlattice unit cell.