Two instances of random access code in the quantum regime

Autor: Sakharwade, Nitica, Studziński, Michał, Eckstein, Michał, Horodecki, Paweł
Rok vydání: 2022
Předmět:
Zdroj: New J. Phys. 25 053038 (2023)
Druh dokumentu: Working Paper
DOI: 10.1088/1367-2630/acd716
Popis: We consider two classes of quantum generalisations of Random Access Code (RAC) and study lower bounds for probabilities of success for such tasks. It provides a useful framework for the study of certain information processing tasks with constrained resources. The first class is based on a random access code with quantum inputs and output known as No-Signalling Quantum RAC (NS-QRAC) [A. Grudka et al. Phys. Rev. A 92, 052312 (2015)], where unbounded entanglement and constrained classical communication are allowed, which can be seen as quantum teleportation with constrained classical communication, for which we provide a quantum lower bound. We consider two modifications to the NS-QRAC scenario, first where unbounded entanglement and constrained quantum communication is allowed and, second where bounded entanglement and unconstrained classical communication are allowed, where we find a monogamy relation for the transmission fidelities, which -- in contrast to the usual communication schemes -- involves multiple senders and a single receiver. We provide lower bounds for these scenarios. The second class is based on a random access code with a quantum channel and shared entanglement [A. Tavakoli et al. PRX Quantum 2 (4) 040357 (2021)]. We study the set of tasks where two inputs made of two digits of $d$-base are encoded over a qudit and a maximally entangled state, which can be seen as quantum dense coding with constrained quantum communication, for which we provide quantum lower bounds for $d=2,3,4$. The encoding employed utilises Gray codes.
Comment: Version after Referee report corrections, 16 Pages, 11 Figures. Paper is published New Journal of Physics (2023). Version 3 and Version 2 are identical other than corrected reference number
Databáze: arXiv