ABSTRACT
This chapter lays out the groundwork for the properties of the most-used three-photon-entangled states so that we can refer back to them later. Three-party states naturally form a two-dimensional network, like the internet, that two-party states miss out on. The chapter discusses the two states are the Greenberger–Horne–Zeilinger (GHZ) state and the W-state. As the experimentalists made better and better Bell testers, the theorists made ever more improbable hidden variable theories. These gave rise to loopholes because while these theories were unlikely, they were not impossible. One of the premier places in the world to do theoretical physics is the Perimeter Institute in Canada. A few years back, in a night-of-the-long-knives moment, all but one of the quantum foundations scientists were summarily sacked, so the upper administration could replace them with even more superstring theorists.
