Worlds first quantum router... sort of

If you’ve ever been curious what students at Tsinghua University in China do in their spare time you can stop, because apparently they build and test the world’s first quantum data router. To be fair, the student researchers probably don’t actually have any free time and the router is more a “first proof-of-principle demonstration” than an actual quantum router. The router itself is little more than a collection of half-silvered-mirrors and waveplates and can only control a qubit at a time. Starting with a single photon the researchers created an entangled pair of lower-energy photons. The first ,“control,” photon dictates the course the entangled pair travels through the router based on it polarization. Because the first photon in the entangled pair dictates course, the second photon never has its altered by the routing process and is thus capable of carrying a single qubit of information. While not practical for use the router is an interesting step for quantum communications.