Classical simulation of entanglement swapping with bounded communication

TL;DR

This paper demonstrates that the quantum process of entanglement swapping, which creates nonlocal correlations between particles without prior interaction, can be simulated classically with only 9 bits of communication, even under strict independence assumptions.

Contribution

It provides the first known classical simulation of entanglement swapping with bounded communication in the bilocal scenario, establishing an upper bound on its nonlocality.

Findings

Classical simulation of entanglement swapping with 9 bits of communication.

Simulation is possible even with independent sources and no prior shared randomness.

Establishes an upper bound on the nonlocality of entanglement swapping.

Abstract

Entanglement appears under two different forms in quantum theory, namely as a property of states of joint systems and as a property of measurement eigenstates in joint measurements. By combining these two aspects of entanglement, it is possible to generate nonlocality between particles that never interacted, using the protocol of entanglement swapping. We show that even in the more constraining bilocal scenario where distant sources of particles are assumed to be independent, i.e. to share no prior randomness, this process can be simulated classically with bounded communication, using only 9 bits in total. Our result thus provides an upper bound on the nonlocality of the process of entanglement swapping.