title: Assisted Distillation of Quantum Coherence.
abstract: We introduce and study the task of assisted coherence distillation. This task arises naturally in bipartite systems where both parties work together to generate the maximal possible coherence on one of the subsystems. Only incoherent operations are allowed on the target system, while general local quantum operations are permitted on the other; this is an operational paradigm that we call local quantum-incoherent operations and classical communication. We show that the asymptotic rate of assisted coherence distillation for pure states is equal to the coherence of assistance, an analog of the entanglement of assistance, whose properties we characterize. Our findings imply a novel interpretation of the von Neumann entropy: it quantifies the maximum amount of extra quantum coherence a system can gain when receiving assistance from a collaborative party. Our results are generalized to coherence localization in a multipartite setting and possible applications are discussed.
authors.affiliation: Department of Physics and Astronomy, Southern Illinois University, Carbondale, Illinois 62901, USA.
authors.forename: E
authors.initials: E
authors.lastname: Chitambar
authors.affiliation: ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Streltsov
authors.affiliation: ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Rana
authors.affiliation: ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Spain.
authors.forename: M N
authors.initials: MN
authors.lastname: Bera
authors.affiliation: School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Adesso
authors.affiliation: ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Spain.|ICREA-Institució Catalana de Recerca i Estudis Avançats, Lluis Companys 23, E-08010 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Lewenstein