Conductance fluctuations and non-diffusive motion in GaAs/AlGaAs heterojunction wires

The authors have measured the magnetoresistance of one-dimensional GaAs heterojunction wires at temperatures down to 0.04 K and in magnetic fields of up to 1.2 T. At low magnetic fields they observe universal conductance fluctuations with a temperature dependence consistent with a temperature independent phase breaking length. This unexpected result is not predicted by theory and they speculate that it may be related to the breakdown of diffusive motion.