Local tests of global entanglement and a counterexample to the generalized area law
arXiv:1410.0951 · doi:10.1109/FOCS.2014.34
Abstract
We introduce a technique for applying quantum expanders in a distributed fashion, and use it to solve two basic questions: testing whether a bipartite quantum state shared by two parties is the maximally entangled state and disproving a generalized area law. In the process these two questions which appear completely unrelated turn out to be two sides of the same coin. Strikingly in both cases a constant amount of resources are used to verify a global property.
21 pages, to appear FOCS 2014