Propagation Around a Bend in a Multichannel Electron Waveguide.

We have measured the four terminal magnetoresistance of extremely high mobility, one dimensional wires fabricated in GaAs/AlGaAs heterostructures in which only a few transverse, one dimensional subbands carry the current, and simulated the measurement numerically. Our observations reveal that in these devices the average resistance can be predominately associated with scattering from the leads used for the measurement. The effect of a lead on the resistance decays on a length scale much shorter than the elastic mean free path estimated from the mobility.