Quantum cost for sending entanglement

TL;DR

This paper investigates the minimal quantum resources required to establish entanglement between distant parties, demonstrating that quantum correlations are essential and providing an optimal protocol for entanglement distribution.

Contribution

It introduces a fundamental quantum cost measure for entanglement creation and proves its intrinsic quantum nature, offering an optimal distribution protocol.

Findings

Quantum cost is intrinsically quantum and tied to quantum correlations.

An optimal protocol for entanglement distribution is established.

Quantum correlations are essential resources for establishing entanglement.

Abstract

Establishing quantum entanglement between two distant parties is an essential step of many protocols in quantum information processing. One possibility for providing long-distance entanglement is to create an entangled composite state within a lab and then physically send one subsystem to a distant lab. However, is this the "cheapest" way? Here, we investigate the minimal "cost" that is necessary for establishing a certain amount of entanglement between two distant parties. We prove that this cost is intrinsically quantum, and is specified by quantum correlations. Our results provide an optimal protocol for entanglement distribution and show that quantum correlations are the essential resource for this task.