Anomalous temperature dependence of the dephasing time in mesoscopic kondo wires.
We present measurements of the magnetoconductance of long and narrow quasi-one-dimensional gold wires containing magnetic iron impurities in a temperature range extending from 15 mK to 4.2 K. The dephasing rate extracted from the weak antilocalization shows a pronounced plateau in a temperature region of 300-800 mK, associated with the phase breaking due to the Kondo effect. Below the Kondo temperature, the dephasing rate decreases linearly with temperature, in contradiction with standard Fermi-liquid theory. Our data suggest that the formation of a spin glass due to the interactions between the magnetic moments is responsible for the observed anomalous temperature dependence.
Schopfer
Félicien
F
Centre de Recherches sur les Très Basses Températures, BP 166 X, 38042 Grenoble CEDEX 9, France.
Bäuerle
Christopher
C
Rabaud
Wilfried
W
Saminadayar
Laurent
L