Observation of the Nyquist phase-coherence time in thin Au-Pd wires

We have studied the magnetoresistance of Au-Pd wires with diameters of order 500 Å, in the temperature range 1–15 K. These measurements yield an electron phase-coherence time which varies with temperature as $T^{\mathrm{-}2/3}$. This temperature dependence suggests that we have observed the one-dimensional ‘‘Nyquist’’ time predicted theoretically by Altshuler and coworkers.