A Young-type experiment using a single-electron source and an independent atomic-size two-center interferometer: the realization of a thought experiment

Interferences caused by a single electron impacting on an independent double-center scatterer, which plays the role of an atomic-size double-slit system, are experimentally evidenced for the first time. The electron originates from the autoionization of doubly excited 2lnl' (n ≥ 2) configurations of He following a double charge exchange process by He2+ ions impinging on H2 molecules. Well-defined oscillations are visible in the angular distribution of the electrons emitted towards the receding H+ protons. The presence of these oscillations demonstrates that a single electron interferes with itself. This is analogous to the famous 'thought' experiment imagined and discussed by Feynman in 1963, in which the quantum nature of the electron was illustrated by making it traverse an atomic-size double-slit arrangement