On the Horizon: A Quantum Internet

A team of scientists in Innsbruck, Austria, made an important step toward distributed quantum computing with cavities linking remote atom-based registers. They demonstrated precise control of the coupling of each of two trapped ions to the mode of an optical resonator. A key goal in quantum computing is the demonstration of a quantum network, that is, a framework for distribution and remote processing of quantum information. One promising model for such a network consists of local processors linked to one another over long distances via optical fiber. Each local processor, consisting of several quantum bits, would be confined between two highly reflective mirrors. These mirrors form an optical resonator, which functions as a coherent interface between light (in the fiber) and matter (the quantum bits). Significant experimental progress has been made in recent years with single atoms as quantum bits in optical resonators.