For the first time, researchers have managed to show the diffraction of atoms through a crystal. Researchers from the Institute of Quantum Technologies and the University of Vienna have demonstrated diffractions of hydrogen and helium atoms using a one-atom-thick sheet of graphene. The atoms are shot perpendicularly at the graphene sheet at high energy. While this should damage the crystal, the team succeeded in accomplishing this breakthrough without the damage.
According to the team: "... despite decades of research, crystalline gratings used since the first atomic diffraction experiments are still unmatched regarding momentum transfer. So far, diffraction through such gratings has only been reported for subatomic particles, but never for atoms". Their recent work made use of graphene to change this situation.
“Despite the atoms' high kinetic energy and coupling to the electronic system of graphene, we observe diffraction patterns featuring coherent scattering of up to eight reciprocal lattice vectors. Diffraction in this regime is possible due to the short interaction time of the projectile with the atomically-thin crystal, limiting the momentum transfer to the grating,” the researchers wrote in the paper. It seems that the peculiarities of quantum mechanics enable the higher energy atoms to more easily diffract through the crystal without destroying it.
The scientists expect these findings to inspire studies of decoherence in an uncharted energy regime and the development of new matter-wave-based sensors.