Length-Independent Voltage Fluctuations in Small Devices

Conductance fluctuations in one-dimensional lines of length $L$ shorter than the phase-coherence length $L_{\phi }$ are not universal but diverge as $L^{-2\mathrm{}}$. Using the Onsager relations and voltage additivity, we show that the voltage fluctuations are independent of the distance between voltage probes. The antisymmetric (Hall-type) contribution to the voltage fluctuations is constant for all values of $L$. Measurements of the voltage fluctuations and correlation function between different regions in Au and Sb lines confirm these results.