Experimental observation of coherent-information superadditivity in a dephrasure channel
Abstract
We present an experimental approach to construct a dephrasure channel, which contains both dephasing and erasure noises, and can be used as an efficient tool to study the superadditivity of coherent information. By using a three-fold dephrasure channel, the superadditivity of coherent information is observed, and a substantial gap is found between the zero single-letter coherent information and zero quantum capacity. Particularly, we find that when the coherent information of n channel uses is zero, in the case of larger number of channel uses, it will become positive. These phenomena exhibit a more obvious superadditivity of coherent information than previous works, and demonstrate a higher threshold for non-zero quantum capacity. Such novel channels built in our experiment also can provide a useful platform to study the non-additive properties of coherent information and quantum channel capacity.
Keywords
Cite
@article{arxiv.2003.13000,
title = {Experimental observation of coherent-information superadditivity in a dephrasure channel},
author = {Shang Yu and Yu Meng and Raj B. Patel and Yi-Tao Wang and Zhi-Jin Ke and Wei Liu and Zhi-Peng Li and Yuan-Ze Yang and Wen-Hao Zhang and Jian-Shun Tang and Chuan-Feng Li and Guang-Can Guo},
journal= {arXiv preprint arXiv:2003.13000},
year = {2020}
}