Quantum Communications Made Easy: Deterministic Models of Bosonic Channels

Abstract

Information theory establishes the ultimate limits on performance for noisy communication systems [Shannon48]. An accurate model of a physical communication device must include quantum effects, but typically including these makes the theory intractable. As a result communication capacities are not known, even for transmission between two users connected by an electromagnetic waveguide subject to gaussian noise. Here we present an exactly solvable model of communications with a fully quantum electromagnetic field. This allows us to find explicit expressions for all the point-to-point capacities of a noisy quantum channel, with implications for quantum key distribution, and fiber optical communications. We also develop a theory of quantum communication networks by solving some rudimentary quantum networks for broadcasting and multiple access. When possible, we compare the predictions of our new model with those of the orthodox quantum gaussian model and in all cases we find capacities in agreement to within a constant number of bits. Thus, in the limit of high signal to noise ratios our simple model captures the relevant physics of gaussian models while remaining amenable to detailed analysis,

9 pages, 10 figures

References in corpus (6)

• Quantum Communication With Zero-Capacity Channels
• Quantum Capacities of Bosonic Channels
• Gaussian bosonic synergy: quantum communication via realistic channels of zero quantum capacity
• Classical capacity of bosonic broadcast communication and a new minimum output entropy conjecture
• Extensive nonadditivity of privacy
• Information trade-offs for optical quantum communication

Cited by in corpus (4)

• Bounding the energy-constrained quantum and private capacities of phase-insensitive bosonic Gaussian channels
• Superadditivity of private information for any number of uses of the channel
• Process output nonclassicality and nonclassicality depth of quantum-optical channels
• Quantum-optical channels that output only classical states