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Bidirectional coherent classical communication

Harrow, Aram W. and Leung, Debbie W. (2005) Bidirectional coherent classical communication. Quantum Information and Computation, 5 (4-5). pp. 380-395. ISSN 1533-7146.

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A unitary interaction coupling two parties enables quantum or classical communication in both the forward and backward directions. Each communication capacity can be thought of as a tradeoff between the achievable rates of specific types of forward and backward communication. Our first result shows that for any bipartite unitary gate, bidirectional coherent classical communication is no more difficult than bidirectional classical communication — they have the same achievable rate regions. Previously this result was known only for the unidirectional capacities (i.e., the boundaries of the tradeoff). We then relate the tradeoff for two-way coherent communication to the tradeoff for two-way quantum communication and the tradeoff for coherent communication in one direction and quantum communication in the other.

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Additional Information:© 2005 Rinton Press. Received December 16, 2004. Revised May 11, 2005. Communicated by H-K Lo. We are grateful to the Perimeter Institute for their hospitality while we did this work. Feedback from the anonymous referees was much appreciated. Thanks to Igor Devetak, Andreas Winter, and Jon Yard for useful discussions, especially on the relation between the worst-case and the average-case errors and on the significance of [23]. AWH acknowledges partial support from the NSA and ARDA under ARO contract DAAD19-01-1-06. DWL acknowledges support from the Tolman Endowment Fund, the Croucher Foundation, and the US NSF under grant no. EIA-0086038.
Funding AgencyGrant Number
Army Research Office (ARO)DAAD19-01-1-06
Tolman Endowment FundUNSPECIFIED
Croucher FoundationUNSPECIFIED
Subject Keywords:bidirectional channels; channel capacities; coherent classical communication
Record Number:CaltechAUTHORS:20110714-142639427
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:24428
Deposited By: Tony Diaz
Deposited On:26 Oct 2011 18:14
Last Modified:26 Dec 2012 13:24

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