Nonlocality in unambiguous pure-state identification without classical knowledge

TL;DR

This paper investigates the limits of unambiguous pure-state identification in bipartite systems without classical knowledge, demonstrating that local operations cannot match the success probability of global measurements.

Contribution

It reveals the fundamental gap between local and global measurement schemes in unambiguous state identification without classical information.

Findings

Global measurements outperform local operations in success probability

Local operations with classical communication are insufficient for optimal identification

Unambiguous identification success probability is bounded by measurement scheme type

Abstract

For two bipartite pure states, we consider the problem of unambiguous identification without classical knowledge on the states. The optimal success probability by means of local operations and classical communication is shown to be less than the maximum attainable by the global measuring scheme.