Transport along doping quantum wires in silicon

The electronic structure and transport properties of doping quantum wires (DQWs) in silicon are studied theoretically in the effective-mass approximation and the local-density-functional formalism. In DQWs oriented along 110, all six valleys are found to be occupied and the system is in the electric quantum limit for realistic doping densities. The effect of scattering from disordered discrete donor charges is calculated in the relaxation-time approximation, taking into account many-body and impurity-scattering effects on the dielectric function in the local-density approximation and the self-consistent Born approximation, respectively. In spite of the strong binding of the electrons to the doping charge, the reduction of the scattering phase space due to quasi-one-dimensionality can lead to an enhancement of the mobility relative to heavily doped bulk silicon.