Demonstrations of two-slit electron interference

Akira Tonomura, Junji Endo, Tsuyoshi Matsuda +2 more

The wave–particle duality of electrons was demonstrated in a kind of two-slit interference experiment using an electron microscope equipped with an electron biprism and a position-sensitive electron-counting system. Such an experiment has been regarded as a pure thought experiment that can never be realized. This article reports an experiment that successfully recorded the actual buildup process of the interference pattern with a series of incoming single electrons in the form of a movie.

Stefano Frabboni, G. C. Gazzadi, G. Pozzi

Ralph F. Baierlein, Vacek Miglus

Lebo Zhang, H. Q. Xu

We report on a theoretical study of the quantum interference behaviour of electron flow from a double-slit device made from a semiconductor two-dimensional electron gas (2DEG) system with the slit widths in the quantum conductance regime. The device consists of a double slit and a single slit in a configuration where the single slit is placed on the source side of the double slit. The wavefunctions of electrons passing through the double-slit structure are calculated on the basis of a scattering matrix method. It is found that including a single slit between the double slit and the source contact in the device is essential for the observation of interference fringes of electron flow in a double-slit experiment with a 2DEG. When only the lowest mode is open for conduction in the individual slits, the interference patterns of electron flow from the double slit resemble the results of a conventional Young's double-slit experiment well. When several modes are open for conduction in the individual slits, the interference patterns of electron flow from the double slit are dominated by the interference of electrons flowing through the highest index open modes in the slits. As a result of the existence of multiple-lobe structures in electron flow from these high index open modes, these interference patterns, in general, show rather complex structures. We also discuss the characteristics of interference patterns in the near-and far-field regimes and the dependence of the fringe spacing on the slit distance in the double slit.

Pedro Sancho

Andrew Das Arulsamy

We construct proper microscopic propositions to consistently capture and explain the interference patterns obtained for electrons and photons, detected individually or otherwise, in one- and two-slit experiments. We propose that for single-photon detections (after time integration), no interference pattern is obtained if one uses non-transparent slit material with slit holes (not diffraction slits). The non-transparent slit material does not permit photons to transmit, reflect internally nor refract. However, the same slit holes can produce the usual interference pattern with electromagnetic waves due to interfering in-phase and out-of-phase light waves. As for the electrons, detected individually or not, partial interference patterns can always be obtained from the two-slit experiment when one of the slits is closed (one at a time), which then can be manually overlapped to produce the complete interference pattern of a double-slit experiment. These new theoretically constructed experimental results for photons and electrons can be readily verified with our current technology using suitable optically non-transparent (for photons) and highly insulating (for electrons) slit materials.