Simple molecules mimic double slits

Simple molecules mimic double slits. The double slit experiment, in which a coherent beam of particles diffracts through closely spaced slits to produce interference fringes, is perhaps the simplest and most famous demonstration of wave–particle duality. It has been shown to work with photons, electrons, and even the comparatively massive buckminsterfullerenes. According to a theory outlined by Howard Cohen and Ugo Fano nearly 50 years ago, interference fringes should also result from the photoionization of a diatomic molecule, provided electrons on each atom are ejected simultaneously and bestowed with enough kinetic energy that their wavelengths are similar to the interatomic distance, as illustrated here. Unfortunately, the direct approach—fixing molecules’ orientation in space, photoionizing them, and detecting fluctuations in the angular distribution of electron density—is, for the most part, impractical. Instead, an international team of scientists led by Fernando Martín (Autonomous University of Madrid) used an elaborate first-principles theory to...