Sequential random access codes and self-testing of quantum measurement instruments

Autor: Karthik Mohan, Armin Tavakoli, Nicolas Brunner
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: New Journal of Physics, Vol 21, Iss 8, p 083034 (2019)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/ab3773
Popis: Quantum random access codes (QRACs) are key tools for a variety of protocols in quantum information theory. These are commonly studied in prepare-and-measure scenarios in which a sender prepares states and a receiver measures them. Here, we consider a three-party prepare-transform-measure scenario in which the simplest QRAC is implemented twice in sequence based on the same physical system. We derive optimal trade-off relations between the two QRACs. We apply our results to construct semi-device independent self-tests of quantum instruments, i.e. measurement channels with both a classical and quantum output. Finally, we show how sequential QRACs enable inference of upper and lower bounds on the sharpness parameter of a quantum instrument.
Databáze: Directory of Open Access Journals