Recent Contributions of Electron Interferometry to Wave—Particle Duality

Louis de Broglie’s wave-particle duality hypothesis, published in his famous paper(1) in 1924, was verified for electrons only 3 years later by Davisson and Germer(2) and Thomson.(3) No interferometer was available at that time to measure the very short electron wavelengths predicted by the de Broglie relation. The idea underlying their experiment to prove the hypothesis was that if electrons are in some sense represented by waves, they should undergo diffraction from crystalline lattices in a way almost identical to X rays. Crystalline lattices of appropriate periodicity were at hand and therefore a diffraction experiment provided the first evidence of wave-particle duality.