Are transport anomalies in ‘‘electron waveguides’’ classical?

We test the implicit prediction of a recent classical model that transport anomalies in ballistic multiprobe conductors---the last plateau, quenching, and the negative bend resistance---should scale with Fermi momentum, pF. Data from junctions defined by adiabatic lateral potentials (having corners with radii of curvature rJ>{}/pF) qualitatively scale classically; departures observed are attributed to momentum-memory loss from random scattering. With more abrupt (square-cornered) junctions, however, nonclassical pF dependence emerges.