Matter Waves

Abstract

In the previous reading selection, Davisson interpreted his experiments on the scattering of electrons from a nickel crystal using De Broglie’s recently developed theory of matter waves.

De Broglie claimed that just as light waves could exhibit particle-like properties (in the form of photons), so too, particles (such as electrons) could exhibit wave-like properties. This counter-intuitive idea of wave-particle duality had been recently employed by Compton in order to make sense of the scattering of photons from electrons, and it would soon form the basis of Schrödinger’s wave-mechanical formulation of quantum theory. In the reading selection below, Davisson continues to discuss his famous electron scattering experiments. You will notice that he treats the top layer of atoms in the nickel crystal as a diffraction grating whose spacing depends on the orientation of the crystal. Do his results provide quantitative (as opposed to merely qualitative)support for De Broglie’s theory of matter waves? What conclusion does he finally draw from his data?

The electron as a particle is too well established to be discredited by a few experiments with a nickel crystal.

—Clinton Davisson