Entanglement-redistribution boxes

TL;DR

This paper develops a framework to analyze the classical communication requirements of entanglement redistribution operations like entanglement swapping and explores their potential to facilitate classical communication.

Contribution

It introduces a new framework for studying the communication costs of entanglement-redistribution primitives and compares their capabilities to established quantum protocols.

Findings

Entanglement swapping requires more communication than it can transmit.

Entanglement swapping is less effective for signaling than quantum teleportation.

The framework clarifies the resource costs of entanglement redistribution operations.

Abstract

We establish a framework to study the classical-communication properties of primitive local operations assisted by classical communication which realize various redistributions of entanglement, like, e.g., entanglement swapping. On the one hand, we analyze what local operations and how much classical communication are needed to perform them. On the other hand, we investigate whether and to what extent such primitives can help to establish classical communication when they are used in the form of black boxes available to spatially-separated users. In particular, we find that entanglement swapping costs more communication than it can signal; in this sense, entanglement swapping is a weaker primitive than quantum teleportation.