Creating User Friendly Photon Pairs

For many researchers, quantum entanglement has become merely a tool that is being put to use, or a resource that has to be accounted for. For others, like me, entanglement has not lost any of its fascination. Whether it is the fascination we want to explore or a tool that we would like to hone, most of us agree that it would be fantastic to have something like an entanglement laser pointer. Push a button on a small battery-powered device and out come your entangled photon pairs. A dream? Fabien Boitier at Paris Diderot University–Paris 7, France, and co-workers have just brought this dream much closer to reality. In Physical Review Letters [1] they write about how they realized an electrically powered semiconductor source of photon pairs. While they have not