Entanglement as a resource for local state discrimination in multipartite systems

TL;DR

This paper investigates the role of entangled states as resources for local measurements in multipartite quantum systems, revealing limitations compared to bipartite systems and establishing a connection with state discrimination.

Contribution

It demonstrates that most multipartite systems lack a universal entangled resource for all measurements, contrasting with bipartite cases, and links local state transformation to entanglement-assisted discrimination.

Findings

Most multipartite systems cannot be universally measured with a single entangled state.

In bipartite systems, a maximally entangled state suffices as a universal resource.

The study establishes an equivalence between local state transformation and entanglement-assisted discrimination.

Abstract

We explore the question of using an entangled state as a universal resource for implementing quantum measurements by local operations and classical communication (LOCC). We show that for most systems consisting of three or more subsystems, there is no entangled state from the same space that can enable all measurements by LOCC. This is in direct contrast to the bipartite case, where a maximally entangled state is an universal resource. Our results are obtained showing an equivalence between the problem of local state transformation and that of entanglement-assisted local unambiguous state discrimination.