Scientists observe and control ultrafast surface waves on graphene

Imagine standing by a lake and throwing a stone into the water. Waves spread out in circular patterns and can reflect at obstacles and boundaries. Researchers at the University of Regensburg, in collaboration with colleagues from Milan and Pisa, have recreated this everyday phenomenon in a fascinating miniature world: They observed the propagation of waves—not on water but in an "electron sea"—using one of the fastest slow-motion cameras on the nanoscale. The study is published in Nano Letters.