Light is an extremely useful tool for quantum communication, but it has one major disadvantage: it usually travels at the speed of light and cannot be kept in place. A team of scientists at the Vienna University of Technology has now demonstrated that this problem can be solved -- not only in strange, unusual quantum systems, but in the glass fiber networks we are already using today.
By coupling atoms to glass fibers light was slowed down to a speed of 180 km/h. The team even managed to bring the light to a complete stop and to retrieve it again later. This technology is an important prerequisite for a future glassfiber-based quantum-internet, in which quantum information can be teleported over great distances.