Shubnikov—de Haas Oscillations in a Semiconductor Superlattice

We have observed Shubnikov---de Haas oscillations associated with the quantum sub-bands created in superlattices made of periodic layers of GaAs and Ga_1-xAlₓAs. By controlling the periodic potential profile, a variety of sample with sub-bands of different degrees of two-dimensionality have been prepared for investigation. The observed oscillatory behaviors agree with those predicted from the Fermi surfaces calculated theoretically on the basis of the superlattice configuration and the electron concentration.