Zero-dimensional states in macroscopic resonant tunneling devices

Abstract

We demonstrate that it is possible to observe transport through individual tunneling channels due to zero-dimensional states in large area resonant tunneling devices (RTD). These localized states are found to be related to the presence of donor impurities in the vicinity of the quantum well but their binding energies are larger than that due to a single isolated hydrogenic donor. The states give rise to additional peaks in current voltage below the threshold for the main resonant peak. These peaks are visible in RTD with essentially any lateral dimension provided the current is measured with sufficient sensitivity.