title: Faithful qubit distribution assisted by one additional qubit against collective noise.
abstract: We propose a distribution scheme of polarization states of a single photon over a collective-noise channel. By adding one extra photon with a fixed polarization, we can protect the state against collective noise via a parity-check measurement and postselection. While the scheme succeeds only probabilistically, it is simpler and more flexible than the schemes utilizing decoherence-free subspace. An application to the Bennett-Brassard 1984 protocol through a collective-noise channel, which is robust to the Trojan horse attack, is also given.
authors.affiliation: Division of Materials Physics, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan. yamamoto@mp.es.osaka-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: J
authors.initials: J
authors.lastname: Shimamura
authors.forename: S K
authors.initials: SK
authors.lastname: Ozdemir
authors.forename: M
authors.initials: M
authors.lastname: Koashi
authors.forename: N
authors.initials: N
authors.lastname: Imoto