Remote Controlled Entanglement

Quantum entanglement is not only one of the most puzzling features of quantum mechanics, but it is also a useful resource that can be consumed to realize tasks that would otherwise be impossible. Famous examples are quantum teleportation and quantum cryptography, which are most useful when entanglement is shared between remote parties. Although nearby entangled states can routinely be created using a host of physical systems, optical photons are the natural choice for entangling spatially separated systems. But in Physical Review Letters, Nicolas Roch, from the University of California at Berkeley, and colleagues reported realizing this feat using microwave radiation to measure, and thereby entangle, superconducting circuits separated by 1.3 meters of coaxial cable [1].