title: Catalytic Decoupling of Quantum Information.
abstract: The decoupling technique is a fundamental tool in quantum information theory with applications ranging from thermodynamics to many-body physics and black hole radiation whereby a quantum system is decoupled from another one by discarding an appropriately chosen part of it. Here, we introduce catalytic decoupling, i.e., decoupling with the help of an independent system. Thereby, we remove a restriction on the standard decoupling notion and present a tight characterization in terms of the max-mutual information. The novel notion unifies various tasks and leads to a resource theory of decoupling.
authors.affiliation: Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø.
authors.forename: Christian
authors.initials: C
authors.lastname: Majenz
authors.affiliation: Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Mario
authors.initials: M
authors.lastname: Berta
authors.affiliation: Faculty of Informatics, Masaryk University, Brno, Czech Republic.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dupuis
authors.affiliation: Institute for Theoretical Physics, ETH Zurich, 8093 Zürich, Switzerland.
authors.forename: Renato
authors.initials: R
authors.lastname: Renner
authors.affiliation: Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø.
authors.forename: Matthias
authors.initials: M
authors.lastname: Christandl