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arXiv · 1905.06726

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

Karthik Mohan·Armin Tavakoli·Nicolas Brunner
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Abstract

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.

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Karthik Mohan, Armin Tavakoli, Nicolas Brunner. 2019-08-20. Sequential random access codes and self-testing of quantum measurement instruments. https://doi.org/10.1088/1367-2630%2Fab3773

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