Quantum Conduction on One-Dimensional GaAs Heterostructures

We have studied the magneto-transport properties of 1-d GaAs- AlGaAs rings of mobility 40,000cm sup 2 /Vs. The elastic scattering length is about 2500A while the sample length is of the order of microns, so that we are in the diffusive regime. A variety of quantum phenomena are observed, including negative magneto resistance, hc/e Aharonov-Bohm effect, aperiodic resistance fluctuation, and Shubnikov-de Haas oscillations.