Communication over a quantum channel with feedback

Kaiyuan Ji, Bartosz Regula, Mark M. Wilde

Garry Bowen, Rajagopal Nagarajan

In Shannon information theory the capacity of a memoryless communication channel cannot be increased by the use of feedback from receiver to sender. In this paper the use of classical feedback is shown to provide no increase in the unassisted classical capacity of a memoryless quantum channel when feedback is used across non-entangled input states, or when the channel is an entanglement--breaking channel. This gives a generalization of the Shannon theory for certain classes of feedback protocols when transmitting through noisy quantum communication channels.

Garry Bowen, Rajagopal Nagarajan

In Shannon information theory, the capacity of a memoryless communication channel cannot be increased by the use of feedback from receiver to sender. In this correspondence, the use of classical feedback is shown to provide no increase in the unassisted classical capacity of a memoryless quantum channel when feedback is used across nonentangled input states, or when the channel is an entanglement-breaking channel. This gives a generalization of the Shannon theory for certain classes of feedback protocols when transmitting through noisy quantum communication channels.

Theresa Jacqueline Coe

Garry Bowen, Rajagopal Nagarajan

In Shannon information theory the capacity of a memoryless communication channel cannot be increased by the use of feedback. The use of classical feedback is shown to provide no increase in the classical capacity of a memoryless quantum channel when feedback is used across nonentangled input states, or when the channel is an entanglement-breaking channel

Harald Weinfurter, Anton Zeilinger