title: Relations between Coherence and Path Information.
abstract: We find two relations between coherence and path information in a multipath interferometer. The first builds on earlier results for the two-path interferometer, which used minimum-error state discrimination between detector states to provide the path information. For visibility, which was used in the two-path case, we substitute a recently defined l_{1} measure of quantum coherence. The second is an entropic relation in which the path information is characterized by the mutual information between the detector states and the outcome of the measurement performed on them, and the coherence measure is one based on relative entropy.
authors.affiliation: Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065, USA.|Física Teòrica: Informació i Fenòmens Quàntics, Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Bagan
authors.affiliation: Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065, USA.|Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, USA.
authors.forename: János A
authors.initials: JA
authors.lastname: Bergou
authors.affiliation: Department of Mathematics, New York City College of Technology, 300 Jay Street, Brooklyn, New York 11201, USA.
authors.forename: Seth S
authors.initials: SS
authors.lastname: Cottrell
authors.affiliation: Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065, USA.|Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Hillery