Direct calculation of the nonequilibrium current by a recursive method

Abstract

The spatial distribution of the nonequilibrium current in a series of two point contacts under a finite bias voltage is investigated numerically making use of a recursive Green-function method based on the Keldysh formalism. The results of the current distribution show an interesting behavior such as the existence of vortices in between the two barriers. The temperature dependence of the nonlinear current-voltage characteristic is also studied.