Activation of quantum capacity of Gaussian channels

Abstract

Quantum channels can be activated by a kind of channels whose quantum capacity is zero. This activation effect might be useful to overcome noise of channels by attaching other channels which can enhance the capacity of a given channel. In this work, we show that such an activation is possible by specific positive-partial-transpose channels for Gaussian lossy channels whose quantum capacities are known. We also test more general case involving Gaussian thermal attenuator whose the exact value of quantum capacity has been unknown so far. For a recently suggested narrow upper bound on quantum capacity of the thermal attenuator, we confirm the fact that an activation of quantum capacity occurs as well. This result is applicable for realistic situations in which Gaussian channels describe the noises of communication systems.

arXiv comment5 pages, 4 figures

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Cited by in corpus (11)

• Optimized entropic uncertainty relations for multiple measurements
• Enhanced energy-constrained quantum communication over bosonic Gaussian channels
• Generic nonadditivity of quantum capacity in simple channels
• Entropic singularities give rise to quantum transmission
• Activation and superactivation of single-mode Gaussian quantum channels
• Improving parameters estimation in Gaussian channels using quantum coherence
• Upper bounds on the quantum capacity for general attenuator and amplifier
• Allowing leakage can increase quantum transmission
• Additivity of quantum capacities in simple non-degradable quantum channels
• Quantum Computation and Communication in Bosonic Systems
• Characterization of the measurement uncertainty dynamics in an open system