Terahertz dynamics of a superlattice in crossed electric and magnetic fields

This dissertation presents an experimental investigation of photon-assisted transport in a GaAs/AlGaAs superlattice in the presence of an in-plane magnetic field. In striking contrast to numerous works published over the last two decades, we observe the d.c. saturation current in a superlattice to be very strongly dependent on the strength of an in-plane magnetic field. Furthermore, when the structure is excited at terahertz frequencies, the broadening of the I-V induced by the magnetic field appears to quench the photon assisted transport features.; An intuitive model describing the effects of the magnetic field is developed that accounts for some of the observations semi-quantitatively. It fails to model the large current increases we observe with magnetic field and suggests there is more physics involved.