title: Quantum illumination with Gaussian states.
abstract: An optical transmitter irradiates a target region containing a bright thermal-noise bath in which a low-reflectivity object might be embedded. The light received from this region is used to decide whether the object is present or absent. The performance achieved using a coherent-state transmitter is compared with that of a quantum-illumination transmitter, i.e., one that employs the signal beam obtained from spontaneous parametric down-conversion. By making the optimum joint measurement on the light received from the target region together with the retained spontaneous parametric down-conversion idler beam, the quantum-illumination system realizes a 6 dB advantage in the error-probability exponent over the optimum reception coherent-state system. This advantage accrues despite there being no entanglement between the light collected from the target region and the retained idler beam.
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Si-Hui
authors.initials: SH
authors.lastname: Tan
authors.forename: Baris I
authors.initials: BI
authors.lastname: Erkmen
authors.forename: Vittorio
authors.initials: V
authors.lastname: Giovannetti
authors.forename: Saikat
authors.initials: S
authors.lastname: Guha
authors.forename: Seth
authors.initials: S
authors.lastname: Lloyd
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Maccone
authors.forename: Stefano
authors.initials: S
authors.lastname: Pirandola
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Shapiro