title: Discriminating States: the quantum Chernoff bound.
abstract: We consider the problem of discriminating two different quantum states in the setting of asymptotically many copies, and determine the minimal probability of error. This leads to the identification of the quantum Chernoff bound, thereby solving a long-standing open problem. The bound reduces to the classical Chernoff bound when the quantum states under consideration commute. The quantum Chernoff bound is the natural symmetric distance measure between quantum states because of its clear operational meaning and because it does not seem to share some of the undesirable features of other distance measures.
authors.affiliation: Institute for Mathematical Sciences, Imperial College London, 53 Prince's Gate, London SW7 2PG, United Kingdom.
authors.forename: K M R
authors.initials: KM
authors.lastname: Audenaert
authors.forename: J
authors.initials: J
authors.lastname: Calsamiglia
authors.forename: R
authors.initials: R
authors.lastname: Muñoz-Tapia
authors.forename: E
authors.initials: E
authors.lastname: Bagan
authors.forename: Ll
authors.initials: L
authors.lastname: Masanes
authors.forename: A
authors.initials: A
authors.lastname: Acin
authors.forename: F
authors.initials: F
authors.lastname: Verstraete