THE VOLTAGE DROP ALONG A MESOSCOPIC CONDUCTOR - IS IT A WELL-DEFINED MACROSCOPIC VARIABLE - ARE THERE LIMITATIONS IN ITS DETERMINATION

Abstract

The statistical distribution of the voltage drop along a mesoscopic conductor is calculated in a soluble model: a 3-terminal device consisting of 1D wires. In general, one finds appreciable voltage fluctuations. For instance, the voltage measured at the midpoint of a strongly disordered conductor of a given length falls, with large probability, in the vicinity of the voltage of either terminal! Consequences for a 4-probe measurement are analysed.