Carbon single-electron point source controlled by Coulomb blockade.

The Coulomb blockade effect is commonly used in solid state electronics for the control of electron flow at the single-particle level. Potentially, it allows the creation of single-electron point sources demanded for prospective electron microscopy instruments and other vacuum electronics devices. Here we realize this potential via creation of a stable point electron source composed of a carbon nanowire electrically coupled to a diamond nanotip by a tunnel junction. Using energy spectroscopy analysis, we characterize the electrons liberated from the nanometer scale carbon heterostructures in time and energy domains. Our experimental results demonstrate perfect agreement with theory prediction of Coulomb oscillations of the Fermi level in the nanowire and allow to determine the mechanisms of their suppression. Persistence of the oscillations at room temperature, high intensity field emission with currents up to 1 μA, and other characteristics of our emitters are very promising for practical realization of coherent single-electron guns. Image 1 [ABSTRACT FROM AUTHOR]