Experimental Demonstration of Sequential Quantum Random Access Codes
Abstract
A random access code (RAC) is a strategy to encode a message into a shorter one in a way that any bit of the original can still be recovered with nontrivial probability. Encoding with quantum bits rather than classical ones can improve this probability, but has an important limitation: due to the disturbance caused by standard quantum measurements, qubits cannot be used more than once. However, as recently shown by Mohan, Tavakoli, and Brunner [New J. Phys. 21 083034, (2019)], weak measurements can alleviate this problem, allowing two sequential decoders to perform better than with the best classical RAC. We use single photons to experimentally show that these weak measurements are feasible and nonclassical success probabilities are achievable by two decoders. We prove this for different values of the measurement strength and use our experimental results to put tight bounds on them, certifying the accuracy of our setting. This proves the feasibility of using sequential quantum RACs for quantum information tasks such as the self-testing of untrusted devices.
Cite
@article{arxiv.2001.04885,
title = {Experimental Demonstration of Sequential Quantum Random Access Codes},
author = {Giulio Foletto and Luca Calderaro and Giuseppe Vallone and Paolo Villoresi},
journal= {arXiv preprint arXiv:2001.04885},
year = {2020}
}
Comments
See also the related work arXiv:2001.04768 of Hammad Anwer et al., appearing on arXiv on the same day of the first submission. V2 includes changes after peer review and copy-editing. 9 pages, 6 figures