Structure of Reversible Quantum Channels

Reversibility of quantum channels is a fundamental and key issue in quantum dynamics, with unitary evolutions as prototypical examples. However, there are reversible quantum channels going beyond unitary evolutions. In this work, we provide some characterizations of reversible quantum channels by relating recovery maps of reversible quantum channels with their dual maps. We analyze the structure of recovery maps of reversible quantum channels and provide a decomposition result for them. These structural results reveal some intrinsic aspects of reversible quantum channels and their recovery maps, and may be useful for the study of quantum dynamics and quantum error correction.