Transmission and reflection peaks in multichannel ballistic transport

A multimode theory of coherent electron transport through nanostructures in resonance conditions is developed. It is shown that both peaks and inverted peaks of the transmission probabilities as functions of electron energy, such as have been found by computation in a variety of structures, are equally inherent to a local quasilevel, with Lorentzian forms at the quasilevel energy. Some model systems are also investigated. For both types of resonance, formulas in terms of the quasilevel properties are obtained for the multimode transmission and reflection probabilities, dwell times, and transmission and reflection delay times, versus electron energy. A consequence of the result for dwell times is that when all the itinerant states are filled through the resonance range (for one spin value) their density integrated over the site of the quasilevel is just that of one electron. © 1993 The American Physical Society.