Local tests of global entanglement and a counterexample to the generalized area law

TL;DR

This paper presents a distributed quantum expander technique to efficiently test maximal entanglement and counter the generalized area law, revealing a surprising connection between these problems with constant resource verification.

Contribution

It introduces a novel distributed quantum expander method that simultaneously addresses entanglement testing and disproves the generalized area law, linking these problems in a new way.

Findings

Efficient testing of maximal entanglement with constant resources.

Counterexample to the generalized area law using the proposed technique.

Uncovering a fundamental connection between entanglement verification and area law disproval.

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.