TY - JOUR
T1 - Building Multiple Access Channels with a Single Particle
AU - Zhang, Yujie
AU - Chen, Xinan
AU - Chitambar, Eric
N1 - Funding Information:
This work was supported by NSF Award 1839177. The authors thank Virginia Lorenz, Paul Kwiat, Andreas Winter and Kai Shinbrough for helpful discussions during the preparation of this manuscript.
Publisher Copyright:
© 2022 Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften. All Rights Reserved.
PY - 2022
Y1 - 2022
N2 - A multiple access channel describes a situation in which multiple senders are trying to forward messages to a single receiver using some physical medium. In this paper we consider scenarios in which this medium consists of just a single classical or quantum particle. In the quantum case, the particle can be prepared in a superposition state thereby allowing for a richer family of encoding strategies. To make the comparison between quantum and classical channels precise, we introduce an operational framework in which all possible encoding strategies consume no more than a single particle. We apply this framework to an Nport interferometer experiment in which each party controls a path the particle can traverse. When used for the purpose of communication, this setup embodies a multiple access channel (MAC) built with a single particle. We provide a full characterization of the Nparty classical MACs that can be built from a single particle, and we show that every quantum particle can generate a MAC outside the classical set. To further distinguish the capabilities of a single classical and quantum particle, we relax the locality constraint and allow for joint encodings by subsets of 1 < K ≤ N parties. This generates a richer family of classical MACs whose polytope dimension we compute. We identify a "generalized fingerprinting inequality" as a valid facet for this polytope, and we verify that a quantum particle distributed among N separated parties can violate this inequality even when K = N-1. Connections are drawn between the single-particle framework and multi-level coherence theory. We show that every pure state with K-level coherence can be detected in a semi-device independent manner, with the only assumption being conservation of particle number.
AB - A multiple access channel describes a situation in which multiple senders are trying to forward messages to a single receiver using some physical medium. In this paper we consider scenarios in which this medium consists of just a single classical or quantum particle. In the quantum case, the particle can be prepared in a superposition state thereby allowing for a richer family of encoding strategies. To make the comparison between quantum and classical channels precise, we introduce an operational framework in which all possible encoding strategies consume no more than a single particle. We apply this framework to an Nport interferometer experiment in which each party controls a path the particle can traverse. When used for the purpose of communication, this setup embodies a multiple access channel (MAC) built with a single particle. We provide a full characterization of the Nparty classical MACs that can be built from a single particle, and we show that every quantum particle can generate a MAC outside the classical set. To further distinguish the capabilities of a single classical and quantum particle, we relax the locality constraint and allow for joint encodings by subsets of 1 < K ≤ N parties. This generates a richer family of classical MACs whose polytope dimension we compute. We identify a "generalized fingerprinting inequality" as a valid facet for this polytope, and we verify that a quantum particle distributed among N separated parties can violate this inequality even when K = N-1. Connections are drawn between the single-particle framework and multi-level coherence theory. We show that every pure state with K-level coherence can be detected in a semi-device independent manner, with the only assumption being conservation of particle number.
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U2 - 10.22331/Q-2022-02-16-653
DO - 10.22331/Q-2022-02-16-653
M3 - Article
AN - SCOPUS:85125852063
SN - 2521-327X
VL - 6
JO - Quantum
JF - Quantum
ER -