Single-electron charging and periodic conductance resonances in GaAs nanostructures

Narrow channels interrupted by two controlled potential barriers and having a tunable electron density were made in GaAs, and their conductance was measured at low temperatures. Reproducible and accurately periodic oscillations of the conductance with changing density are found to correspond to the sequential addition of single electrons to the segment of the channel between the barriers. Detailed examination of the line shape of the conductance versus density provides a new insight into the transport mechanism.