Quantum Coherence Witness with Untrusted Measurement Devices
Abstract
Coherence is a fundamental resource in quantum information processing, which can be certified by a coherence witness. Due to the imperfection of measurement devices, a conventional coherence witness may lead to fallacious results. We show that the conventional witness could mistake an incoherent state as a state with coherence due to the inaccurate settings of measurement bases. In order to make the witness result reliable, we propose a measurement-device-independent coherence witness scheme without any assumptions on the measurement settings. We introduce the decoy-state method to significantly increase the capability of recognizing states with coherence. Furthermore, we experimentally demonstrate the scheme in a time-bin encoding optical system.
Cite
@article{arxiv.1908.05022,
title = {Quantum Coherence Witness with Untrusted Measurement Devices},
author = {You-Qi Nie and Hongyi Zhou and Jian-Yu Guan and Qiang Zhang and Xiongfeng Ma and Jun Zhang and Jian-Wei Pan},
journal= {arXiv preprint arXiv:1908.05022},
year = {2019}
}
Comments
13 pages, 7 figures, including Supplemental Material, accepted for publication in Physical Review Letters