Transmission coefficients and Hall resistance in a small cross-shaped semiconductor junction

A method is described that measures both the transmission coefficients and the Hall resistance for a narrow cross. Buttiker's formula relating these quantities has been verified. The amount of collimation is estimated from the magnetoresistance and shown to be small, with approximately=5% more electrons travelling straight on at the cross in zero magnetic field compared with a magnetic field of 0.1 T. This illustrates that the reason for the quenching of the Hall effect here is a scrambling mechanism rather than the collimation mechanism.