Improved lower bound for the two-way-assisted quantum capacity of the bosonic thermal-loss channel
Abstract
The bosonic thermal-loss channel is a fundamental model for quantum communication. This Gaussian channel models the transmission of bosonic systems subject to both loss and thermal noise. It describes many practical systems, including optical fibers, waveguides and free-space links, where background thermal noise is significant. Determining the channel's two-way-assisted quantum capacity, the maximum rate at which quantum information can be transmitted reliably through the channel with two-way classical assistance, remains an open problem. Here, we improve upon the best known lower bound for this capacity for a wide range of channel parameters. We achieve this by combining an improved qubit-bosonic distribution technique with a recently introduced technique for discovering entanglement distillation protocols.
Related
- Strong converse for the quantum capacity of the pure-loss bosonic channel
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- Efficient capacity-achieving entanglement generation with application to pure-loss Bosonic channels
- Classical Capacity of Single-Mode Bosonic Gaussian Channels
- An Improved Upper Bound on the Capacity of the Primitive Diamond Relay Channel
BibTeX
@misc{barber2026improved,
title = {{Improved lower bound for the two-way-assisted quantum capacity of the bosonic thermal-loss channel}},
author = {Matthew Barber and Stefano Pirandola},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.27792},
eprint = {2609.27792},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.27792},
}
RIS
TY - UNPB
TI - Improved lower bound for the two-way-assisted quantum capacity of the bosonic thermal-loss channel
AU - Matthew Barber
AU - Stefano Pirandola
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.27792
UR - https://arxiv.org/abs/2609.27792
AB - The bosonic thermal-loss channel is a fundamental model for quantum communication. This Gaussian channel models the transmission of bosonic systems subject to both loss and thermal noise. It describes many practical systems, including optical fibers, waveguides and free-space links, where background thermal noise is significant. Determining the channel's two-way-assisted quantum capacity, the maximum rate at which quantum information can be transmitted reliably through the channel with two-way classical assistance, remains an open problem. Here, we improve upon the best known lower bound for this capacity for a wide range of channel parameters. We achieve this by combining an improved qubit-bosonic distribution technique with a recently introduced technique for discovering entanglement distillation protocols.
ER -