Flipping the switch
Harvard researchers have succeeded in creating quantum switches that can be turned on and off using a single photon, a technological achievement that could pave the way for creating highly secure quantum networks. Built from single atoms, the first-of-their-kind switches could one day be networked via fiber-optic cables to form the backbone of a “quantum Internet” that allows for perfectly secure communications, said Professor of Physics Mikhail Lukin, who led a team consisting of graduate student Jeff Thompson and postdoctoral fellow Tobias Tiecke to construct the system. Their research is detailed in a recently published paper in the journal Nature. “From a technical standpoint, it’s a remarkable accomplishment,” Lukin said of the advance. “Conceptually, the idea is very simple: Push the conventional light switch to its ultimate limit. What we’ve done here is to use a single atom as a switch that, depending on its state, can open or close the flow...