期刊
PHYSICAL REVIEW A
卷 103, 期 4, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevA.103.042606
关键词
-
资金
- Australian Research Council (ARC) by Centre of Excellence for Engineered Quantum Systems (EQUS) [CE170100009]
- Australian Research Council Discovery Early Career Researcher Award [DE170100712]
- RTP scholarship from the University of Queensland
Quantum mechanics allows operations to be in indefinite causal order, leading to advantages in computational and communication tasks. Through the process matrix formalism, different classical capacities for a bipartite quantum process are formulated, showing a generalization of the Holevo bound. Bidirectional communication cannot exceed the limit of a one-way communication protocol in causally separable processes.
Quantum mechanics allows operations to be in indefinite causal order, leading to advantages in computational and communication tasks. However, basic notions such as communication capacity have not yet been formalized. In light of this, through the process matrix formalism, we formulate different classical capacities for a bipartite quantum process. For one-way communication, we find that general quantum processes satisfy a generalization of the Holevo bound, i.e., we can send, at most, one bit per qubit. The result also holds for processes with indefinite causal order and with shared entanglement between the sender and the receiver. We further extend known bounds to classical channel capacities, showing that general processes cannot outperform causally separable ones. Next, we study bidirectional communication through a causally separable process. Our result shows that a bidirectional protocol cannot exceed the limit of a one-way communication protocol. Finally, we generalize this result to a multiparty broadcast communication protocol through a definite ordered process.
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