title: Noiseless loss suppression in quantum optical communication.
abstract: We propose a protocol for conditional suppression of losses in direct quantum state transmission over a lossy quantum channel. The method works by noiselessly attenuating the input state prior to transmission through a lossy channel followed by noiseless amplification of the output state. The procedure does not add any noise; hence, it keeps quantum coherence. We experimentally demonstrate it in the subspace spanned by vacuum and single-photon states, and consider its general applicability.
authors.affiliation: Department of Optics, Palacký University, 17. listopadu 1192/12, CZ-771 46 Olomouc, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Mičuda
authors.forename: I
authors.initials: I
authors.lastname: Straka
authors.forename: M
authors.initials: M
authors.lastname: Miková
authors.forename: M
authors.initials: M
authors.lastname: Dušek
authors.forename: N J
authors.initials: NJ
authors.lastname: Cerf
authors.forename: J
authors.initials: J
authors.lastname: Fiurášek
authors.forename: M
authors.initials: M
authors.lastname: Ježek
mesh_terms: D008962:Models, Theoretical; D055095:Optics and Photonics / Q000379:methods*; D011789:Quantum Theory