RESONANT TUNNELING IN A QUASI-ONE-DIMENSIONAL WIRE - INFLUENCE OF EVANESCENT MODES

We calculate the transmission coefficients through two point scatters in a quasi-one-dimensional wire as the Fermi energy and distance between scatters are varied. At a subband minimum the standard wave-interference pattern between propagating modes, characteristic of a Fabry-Perot interferometer, is completely suppressed. Instead, we find that the shape of the lowest evanescent waveguide mode determines the electron transmission so that a different pattern of conductance oscillations emerges. If either of the scatters is attractive, the transmission is suppressed abruptly near the "quasidonor" levels formed in the scatterer below each subband minimum.