Gate-controlled conductance oscillations in small one-dimensional electron cavities

Abstract

The low-temperature, low-bias regime of electron transport through narrow channels in semiconductor heterostructures interrupted by a finite number of potential barriers at zero magnetic field, is investigated with a simple model of resonant tunneling of noninteracting electrons in a single one-dimensional subband. By using a generalized wave impedance concept, we calculate the transmission coefficient for electrons passing through such devices, thus providing a satisfactory explanation for the periodic conductance oscillations observed in recent experiments. We also show that the oscillatory behaviour in the current of arrays of submicrometer normal-metal tunnel junctions may be understood as the formation of miniband structures in such coupled electron systems. Our results call into question the dominance of charging effects in small electron resonator devices.