J.K. Gimzewski, T.A. Jung, et al.
Surface Science
Conductance quantization in the absence and in the presence of a magnetic field is discussed for a split-gate constriction with a local potential at the bottleneck forming a saddle. Simple criteria for the occurrence of conductance steps and the accuracy of quantization are given in terms of the curvatures of the saddle. © 1990 The American Physical Society.