Quantum Binary Symmetric Channels

• 来源期刊: 中国物理快报（英文版）
• 学科: 物理学
• 年，卷（期）: 2001,（6）
• 页码范围: 721-723
• 页数: 3页
• 分类号: O4
• 语种: 英文

摘要

Quantum binary symmetric channels are defined via the invariance of fidelity under unitary transformations ofthe input density operators. In this definition, they not only include the most studied case of the depolarizingchannel but also other channels. We investigate the character of the latter and find the maximum of the coherentinformation to estimate the capacities of the channels.