On entanglement and perfect LOCC discrimination of a class of multiqubit states

TL;DR

This paper investigates how entanglement influences the perfect discrimination of multiqubit states via LOCC, revealing that entanglement content does not limit the maximum number of distinguishable states, which depends on the ensemble composition and spatial configuration.

Contribution

It demonstrates that for certain multiqubit states, the maximum LOCC distinguishability is independent of entanglement content and depends on ensemble makeup and spatial arrangement.

Findings

Maximum LOCC distinguishability is independent of entanglement content.

Ensemble composition affects the number of perfectly distinguishable states.

Spatial configuration influences LOCC discrimination capabilities.

Abstract

It is shown that while entanglement remains a significant factor in discriminating a set of mutually orthogonal entangled states perfectly by local operations and classical communication (LOCC), entanglement content is not. In particular, for a class of entangled multi-qubit states, the maximum number of perfectly LOCC distinguishable orthogonal states is shown to be independent of the average entanglement of the states, and the spatial configuration with respect to which LOCC operations may be carried out. It is also pointed out that the make-up of an ensemble, that is, whether it consists only of entangled states or is a mix of both entangled and product states, determines the maximum number of perfectly distinguishable states.