Transport in GaAs/Al x Ga1−x As superlattices with narrow minibands: Effects of interminiband tunneling

Abstract

The results of experimental investigations for the I–V characteristics are presented for superlattices based on GaAs/Al x Ga1−x As with thin barriers in the electric-field region with an intense interminiband tunneling. The regular features for the I–V characteristics are found in the voltage range adequate to the static positive differential conductivity in the superlattice. On the basis of calculations for the Wannier-Stark levels, it is established that the observed features are associated with the resonant tunneling between these levels belonging to quantum wells located at a distance from 6–13 superlattice periods from each other. It is noted that the similar resonant delocalization of Wannier-Stark wave functions can lead to the existence of dynamic negative differential conductivity for the laser type of an appreciable value in such superlattices.