Exploring the limitations of quantum networking through butterfly-based networks

Kieran N. Wilkinson, Thomas P. W. Cope, Stefano Pirandola

Research output: Contribution to journalArticlepeer-review


We investigate the classical and quantum networking regimes of the butterfly network and a group of larger networks constructed with butterfly network blocks. By considering simultaneous multicasts from a set of senders to a set of receivers, we analyze the corresponding rates for transmitting classical and quantum information through the networks. More precisely, we compare achievable rates (i.e., lower bounds) for classical communication with upper bounds for quantum communication, quantifying the performance gap between the rates for networks connected by identity, depolarizing and erasure channels. For each network considered, we observe a range over which the classical rate non-trivially exceeds the quantum capacity. We find that, by adding butterfly blocks in parallel, the difference between transmitted bits and qubits can be increased up to one extra bit per receiver in the case of perfect transmission (identity channels). Our aim is to provide a quantitative analysis of those network configurations which are particularly disadvantageous for quantum networking, when compared to classical communication. By clarifying the performance of these 'negative cases', we also provide some guidance on how quantum networks should be built.
Original languageEnglish
Article number1900103
Number of pages8
JournalAdvanced Quantum Technologies
Issue number3
Early online date9 Dec 2019
Publication statusPublished - 6 Mar 2020

Bibliographical note

© 2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.


  • quant-ph
  • cond-mat.other
  • physics.app-ph

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