Single-electron Coulomb exclusion on the atomic level

The possibility of processing digital information coded by single electrons on the atomic scale is discussed by analyzing the dynamics of one and two electrons within a simple model structure. Specifically, the probability of passage of an electron within a chain of atomic sites through a potential well, either empty or already occupied by another electron, is investigated both analytically and numerically. It is demonstrated that quantum effects can significantly decrease the reliability of the control that one electron has over the propagation of another. For the structure considered, a few tens of atomic sites and a specific choice of the potential well depth are necessary for reliable control.