title: Quantum decoherence of single-photon counters.
abstract: The interaction of a quantum system with the environment leads to the so-called quantum decoherence. Beyond its fundamental significance, the understanding and the possible control of this dynamics in various scenarios is a key element for mastering quantum information processing. Here we report the quantitative probing of what can be called the quantum decoherence of detectors, a process reminiscent of the decoherence of quantum states in the presence of coupling with a reservoir. We demonstrate how the quantum features of two single-photon counters vanish under the influence of a noisy environment. We thereby experimentally witness the transition between the full-quantum operation of the measurement device to the "semi-classical regime", described by a positive Wigner function. The exact border between these two regimes is explicitely determined and measured experimentally.
authors.affiliation: Laboratoire Kastler Brossel, Université Pierre et Marie Curie, Ecole Normale Supérieure, CNRS, Case 74, 4 place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: V
authors.initials: V
authors.lastname: D'Auria
authors.forename: N
authors.initials: N
authors.lastname: Lee
authors.forename: T
authors.initials: T
authors.lastname: Amri
authors.forename: C
authors.initials: C
authors.lastname: Fabre
authors.forename: J
authors.initials: J
authors.lastname: Laurat