Build-up of interference patterns with single electrons

A conventional transmission electron microscope, equipped with a fast recording system able to measure the electron arrival time and the position of single electrons, is used to show the build-up of interference patterns. Two experiments are presented. The first is the electron version of the Grimaldi and Young experiments performed with light, where single electrons strike on an opaque thin wire. Interference fringes are observed in the geometrical shadow of the wire and diffraction effects are clearly displayed at the wire edges. The second, original experiment reports the build-up of two-slit interference patterns with single electrons.