Reference-frame-independent quantum key distribution was proposed to generate a string of secret keys without a shared reference frame. Based on the Bloch sphere, however, the security analysis in previous methods is only independent on azimuthal angle, while a reference frame is determined by both polar angle and azimuthal angle. Here, we propose a 3 \times 3 matrix whose singular values are independent on both polar angle and azimuthal angle, as well as take advantage of quantum discord, to realize a fully reference-frame-independent quantum key distribution. Furthermore, we numerically show that the performance of our method can reduce to the previous one if the key generation basis is calibrated.
@article{arxiv.2305.09404,
title = {Realizing fully reference-frame-independent quantum key distribution by exploiting quantum discord},
author = {Rong Wang and Chun-Mei Zhang},
journal= {arXiv preprint arXiv:2305.09404},
year = {2023}
}