Thermal heating has limited the clock rates of modern electronics for many years. Together with the group of Ulrich Höfer (University of Marburg) and collaborators from Novosibirsk State University and Hiroshima University, the Group of Rupert Huber has now discovered a convincing way out: Electrons at the surface of a topological insulator – unlike a conventional semiconductor – can be accelerated inertia- und dissipation-free by the carrier field of light. We have directly observed this unusual electron motion in the first slow-motion movie of an electronic bandstructure, reaching a time resolution better than a cycle of light. Future
electronics using topology may thus stay cool even at optical clock rates.