FOCS Conference 2014 Conference Paper
Local Tests of Global Entanglement and a Counterexample to the Generalized Area Law
- Dorit Aharonov
- Aram W. Harrow
- Zeph Landau
- Daniel Nagaj
- Mario Szegedy
- Umesh V. Vazirani
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.