Quantum electronic conductance of a terminal junction

We rigorously treat the quantum mechanical propagation of a two-dimensional electron gas through multiterminal junctions. The elements $R_{\mathrm{mn}}$,kl of Büttiker’s global resistance tensor are calculated for ballistic motion. Our results confirm the occurrence of negative resistance observed in recent experiments and predict oscillations of the resistance as a function of ka, where k is the electron Fermi momentum and a is the geometrical dimension of the junction leads.