- Letter
Local entanglement transfer from an entanglement source to multiple pairs of spatially separated observers
Phys. Rev. A 112, L010402 – Published 7 July, 2025
DOI: https://doi.org/10.1103/17s4-rtdm
Abstract
For an efficient usage and deployment of entanglement, we envisage the scenario where a pair of spatially separated observers, Charu and Debu, want to share entanglement without interacting with each other. As a way out, their systems can separately and locally interact with those of Alice and Bob, respectively, who already share an entangled state. We find joint unitaries which, when applied by Alice and a Charu, and by Bob and the corresponding Debu, can transfer entanglement from the Alice-Bob pair to an indefinite number of pairs of Charus and Debus. We also discuss the amount of entanglement that can be transferred to a fixed number of pairs using these unitaries. Moreover, by optimizing over all possible local unitaries, we analyze the maximum number of pairs to which entanglement can be transferred in such a way that each pair gets at least a fixed amount of entanglement. Given the valuable role played by the costly resource, entanglement, in quantum information processing and communication, we expect that our results will have significant impact in quantum technologies.