We consider an open system of free electrons consisting of a small sampleView original: http://arxiv.org/abs/1112.0083
connected to several reservoirs and temperature or voltage probes. We study the
non-linear system of equations which determines the probe parameters. We show
that it has a unique solution which can be computed with a fast converging
iterative algorithm. We illustrate our method with two well-known models: the
three-terminal system and the open Aharovov-Bohm interferometer.