Nonlinear Conductance in the Mesoscopic Regime
David E Khmel'nitskiĭ, A. I. Larkin · Physica Scripta · 1986
Fluctuations of the current-voltage ( IV ) characteristic of a mesoscopic sample are considered. Such a sample can be realized as a junction of two normal metals. The voltage dependence of current is a random function, and the IV -characteristic has a "blades of grass" form on a usual ohmic background. The scale of each "blade" in voltage is of order V c ~ ℏ/τ f e , where τ f is the time of flight through the junction and e is the electron charge. The scale in current δ I depends on the voltage V and temperature T , and of order ( e 2 /ℏ)( VV c ) 1/2 , if V ≫ V c , T / e . As a result, provided the voltage is sufficiently large, there appear regions of negative differential resistance.