Experimental evidence for boundary and impurity scattering related crossover in quasi-ballistic wires

We study the magnetic field dependence of the correlation field Delta B-c and amplitude delta g of the conductance fluctuations, observed in the low-temperature magnetoresistance of a quasi-ballistic split-gate wire. With increasing the fields, there exists a crossover from diffusive to ballistic motions in the quasi-ballistic transport. Scattering processes have been discussed by analyzing a linear field dependence of Delta B-c above the crossover. The crossover behaviors are considered to be a precursor effect on the formation of the edge channel accompanied with a rapid increase of inelastic scattering length I-in.