ELECTRON-CORRELATION EFFECTS IN THE IMPURITY CONDUCTANCE OF DOPED-SEMICONDUCTOR QUANTUM WIRES

The effect of electron correlations in the impurity conductance of the shallow-donor impurity band in a semiconductor quantum wire, connecte d by two ideal leads, is studied by using the Hubbard model in an allo y-analogy approximation. The hopping integral and the intrasite Coulom b interaction energy are estimated numerically from variational wave f unctions for random impurity configurations. For one electron per impu rity, it is shown that there is a considerable reduction in the impuri ty conduction due to electron correlations. For a given impurity conce ntration, the disordered wire turns into an insulator at a much shorte r sample length than that estimated previously by neglecting correlati ons.