Mutual and coherent informations for infinite-dimensional quantum channels

Understand

The work is devoted to study of quantum mutual information and coherent information -- the two important characteristics of quantum communication channel.

• Appropriate definitions of these quantities in the infinite-dimensional case are given and their properties are studied in detail.
• Basic identities relating quantum mutual information and coherent information of a pair of complementary channels are proved.
• An unexpected continuity property of quantum mutual information and coherent information following from the above identities is observed.