title: Amplification, Decoherence, and the Acquisition of Information by Spin Environments.
abstract: Quantum Darwinism recognizes the role of the environment as a communication channel: Decoherence can selectively amplify information about the pointer states of a system of interest (preventing access to complementary information about their superpositions) and can make records of this information accessible to many observers. This redundancy explains the emergence of objective, classical reality in our quantum Universe. Here, we demonstrate that the amplification of information in realistic spin environments can be quantified by the quantum Chernoff information, which characterizes the distinguishability of partial records in individual environment subsystems. We show that, except for a set of initial states of measure zero, the environment always acquires redundant information. Moreover, the Chernoff information captures the rich behavior of amplification in both finite and infinite spin environments, from quadratic growth of the redundancy to oscillatory behavior. These results will considerably simplify experimental testing of quantum Darwinism, e.g., using nitrogen vacancies in diamond.
authors.affiliation: Department of Physics, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Zwolak
authors.affiliation: Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.|IBM Watson Research Center, Yorktown Heights, NY 10598, USA.
authors.forename: C Jess
authors.initials: CJ
authors.lastname: Riedel
authors.affiliation: Theoretical Division, MS-B213, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Wojciech H
authors.initials: WH
authors.lastname: Zurek