  Although the Fluctuation-Dissipation framework is a first step to get a
quantum model for electrical noise, the merging of displacement and conduction
currents into the sole current of a series notion like the resistance R(f) does
not help in it this task. Used to handle these currents as orthogonal
components in electromagnetic waves, the usage of the impedance
Z(jf)=R(f)+jX(f) for the noisy device hides the way it interacts with its
thermal bath. In contrast to this, the admittance Y(jf) is a parallel notion
directly linked with the aforementioned interaction that has led us to develop
a discrete model for current fluctuations where single electrons randomly
shuttling between any pair of terminals generate the voltage noise we can
measure between them.
