title: Non-Markovianity and reservoir memory of quantum channels: a quantum information theory perspective.
abstract: Quantum technologies rely on the ability to coherently transfer information encoded in quantum states along quantum channels. Decoherence induced by the environment sets limits on the efficiency of any quantum-enhanced protocol. Generally, the longer a quantum channel is the worse its capacity is. We show that for non-Markovian quantum channels this is not always true: surprisingly the capacity of a longer channel can be greater than of a shorter one. We introduce a general theoretical framework linking non-Markovianity to the capacities of quantum channels and demonstrate how harnessing non-Markovianity may improve the efficiency of quantum information processing and communication.
authors.affiliation: Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Toruń, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Bylicka
authors.affiliation: Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Toruń, Poland.
authors.forename: D
authors.initials: D
authors.lastname: Chruściński
authors.affiliation: Department of Physics and Astronomy, University of Turku, 20014, Turku, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Maniscalco