Particles in a new superlattice material can move like a focused beam of light instead of spreading out like a cloud.

In most materials, excitons scatter and diffuse slowly because they bump into everything in their path. This experiment shows that a specific moiré superlattice can drive these particles to move ballistically. The push comes from a strong repulsion between the excitons and a frozen crystal of electrons. This discovery allows for the creation of ultra-fast information carriers that do not lose energy to heat. It could lead to a new generation of electronics that operate at speeds we previously thought were impossible. We are learning to steer particles with atomic precision.