Propagation around a Bend in a Multichannel Electron Waveguide

We have measured the four-terminal magnetoresistance of an electron waveguide, i.e., a high-mobility wire fabricated in GaAs-AlGaAs heterostructure in which only a few transverse one-dimensional subbands carry the current, and simulated the measurement numerically. We observe that the average resistance increases when the current path bends through a junction at or beyond the voltage terminals because of a change (due to the bend) in the relative transmittance of the few subbands. Our observations reveal that the average resistance is predominantly associated with scattering from the leads used for the measurement.