Quasiballistic Electron Transport in a Three-Dimensional Microconstriction.

Quasiballistic electron transport in three-dimensional microconstrictions in a longitudinal magnetic field is studied. The case where the quantization of the conductance is destroyed by an impurity located in the microconstriction is investigated. The transmission coefficients and a formula for the conductance of such a microconstriction are found. It is shown that the dependence of the conductance G(E) on the electron energy has kinks at the threshold of the steps for which impurity scattering is strong. These kinks contain a pronounced vertical segment of the curve G(E). [ABSTRACT FROM AUTHOR]