Determining quantum coherence with minimal resources
Abstract
We characterize minimal measurement setups for validating the quantum coherence of an unknown quantum state. We show that for a -level system, the optimal strategy consists of measuring orthonormal bases such that each measured basis is mutually unbiased with respect to the reference basis, and together with the reference basis they form an informationally complete set of measurements. We show that, in general, any strategy capable of validating quantum coherence allows one to evaluate also the exact value of coherence. We then give an explicit construction of the optimal measurements for arbitrary dimensions. Finally, we show that the same measurement setup is also optimal for the modified task of verifying if the coherence is above or below a given threshold value.
Cite
@article{arxiv.1708.05597,
title = {Determining quantum coherence with minimal resources},
author = {Claudio Carmeli and Teiko Heinosaari and Sabrina Maniscalco and Jussi Schultz and Alessandro Toigo},
journal= {arXiv preprint arXiv:1708.05597},
year = {2018}
}