Quasiballistic electron transport in a three-dimensional microconstriction

Quasiballistic electron transport in three-dimensional microconstrictions i n a longitudinal magnetic field is studied. The case where the quantization of the conductance Is destroyed by an impurity located in the microconstri ction is investigated. The transmission coefficients and a formula for the conductance of such a microconstriction are found. It is shown that the dep endence of the conductance G(E) on the electron energy has kinks at the thr eshold of the steps for which impurity scattering is strong. These kinks co ntain a pronounced vertical segment of the curve G(E). (C) 2000 MALK "Nauka /Interperiodica".