Voltage dependent conductance and shot noise in quantum   microconstriction with single defects
  The influence of the interference of electron waves, which are scattered by single impurities and by a barrier on nonlinear conductance and shot noise of metallic microconstriction is studied theoretically. It is shown that the these characteristics are nonmonotonic functions on the applied bias. 
Ye.S. Avotina, A. Namiranian, Yu.A. Kolesnichenko