On the Duality of Teleportation and Dense Coding - Felix Leditzky | TQC 2023
Channel: Squid: Schools for Quantum Information Development
Date: 24/08/2023

Felix Leditzky
On the Duality of Teleportation and Dense Coding 

Quantum teleportation is a quantum communication primitive that allows a long-distance quantum channel to be built using pre-shared entanglement and one-way classical communication. However, the quality of the established channel crucially depends on the quality of the pre-shared entanglement. In this work, we revisit the problem of using noisy entanglement for the task of teleportation.  We first show how this problem can be rephrased as a state discrimination problem. In this picture, a quantitative duality between teleportation and dense coding emerges in which every Alice-to-Bob teleportation protocol can be repurposed as a Bob-to-Alice dense coding protocol, and the quality of each protocol can be measured by the success probability in the same state discrimination problem.  One of our main results provides a complete characterization of the states that offer no advantage in one-way teleportation protocols over classical states, thereby offering a new and intriguing perspective on the long-standing open problem of identifying such states. This also yields a new proof of the known fact that bound entangled states cannot exceed the classical teleportation threshold.  Moreover, our established duality between teleportation and dense coding can be used to show that the exact same states are unable to provide a non-classical advantage for dense coding as well.  We also discuss the duality from a communication capacity point of view, deriving upper and lower bounds on the accessible information of a dense coding protocol in terms of the fidelity of its associated teleportation protocol. A corollary of this discussion is a simple proof of the previously established fact that bound entangled states do not provide any advantage in dense coding. Online talk.

July 27, 2023
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TQC 2023 | 24-28 July 2023, University of Aveiro, Portugal
http://tqc-conference.org

18th Conference on the  Theory of Quantum Computation, Communication and Cryptography.

TQC is a leading annual international conference for students and researchers working in the theoretical aspects of quantum information science. The scientific objective is to bring together the theoretical quantum information science community to present and discuss the latest advances in the field.


Organisation:
Squids - Schools for Quantum Information Development  
Universidade de Aveiro: Departamento de Matemática, CIDMA & Fábrica


Sponsors:
Phasecraft, UK
Google Quantum AI, USA
QuSoft, The Netherlands
Quantum for Life Centre, Denmark
Technology Innovation Institute, UAE
ML4Q, Germany
Dulwich Quantum