Electronic properties of the donor states under two-dimensional-conductor and quantum-wire configurations in heavily and orderly doped (GaAs)-(AlAs)

Using the self-consistent pseudopotential method, we have studied the conducting properties of Si donor states in heavily and orderly doped (GaAs${)}_2$-(AlAs${)}_2$ superlattices. The Si donor states are arranged to simulate a two-dimensional-conductor and a one-dimensional quantum-wire structure. We have found that the Si donor states can form one- and two-dimensional conducting channels even in these very-thin-layered superlattices. By analyzing the charge density of the donor states we have also found that the width of the conducting channel is about five atomic layers. In the one-dimensional configuration, the effects of the reduction in dimensionality on the energies and the charge distributions of the donor states are presented. The current density is also calculated to show the channeling properties.