期刊
NATURE COMMUNICATIONS
卷 5, 期 -, 页码 -出版社
NATURE PORTFOLIO
DOI: 10.1038/ncomms6235
关键词
-
资金
- DARPA Quiness Program through US Army Research Office [W31P4Q-12-1-0019]
- JSPS
- SeaKey programme through the US Office of Naval Research [N00014-14-C-0002]
Since 1984, various optical quantum key distribution (QKD) protocols have been proposed and examined. In all of them, the rate of secret key generation decays exponentially with distance. A natural and fundamental question is then whether there are yet-to-be discovered optical QKD protocols (without quantum repeaters) that could circumvent this rate-distance tradeoff. This paper provides a major step towards answering this question. Here we show that the secret key agreement capacity of a lossy and noisy optical channel assisted by unlimited two-way public classical communication is limited by an upper bound that is solely a function of the channel loss, regardless of how much optical power the protocol may use. Our result has major implications for understanding the secret key agreement capacity of optical channels-a long-standing open problem in optical quantum information theory-and strongly suggests a real need for quantum repeaters to perform QKD at high rates over long distances.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据