title: Microwave quantum illumination.
abstract: Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here, we describe and analyze a system for applying this technique at microwave frequencies, a more appropriate spectral region for target detection than the optical, due to the naturally occurring bright thermal background in the microwave regime. We use an electro-optomechanical converter to entangle microwave signal and optical idler fields, with the former being sent to probe the target region and the latter being retained at the source. The microwave radiation collected from the target region is then phase conjugated and upconverted into an optical field that is combined with the retained idler in a joint-detection quantum measurement. The error probability of this microwave quantum-illumination system, or quantum radar, is shown to be superior to that of any classical microwave radar of equal transmitted energy.
authors.affiliation: Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany.
authors.forename: Shabir
authors.initials: S
authors.lastname: Barzanjeh
authors.affiliation: Quantum Information Processing Group, Raytheon BBN Technologies, Cambridge, Massachusetts 02138, USA.
authors.forename: Saikat
authors.initials: S
authors.lastname: Guha
authors.affiliation: QKD Corporation, 60 Saint George Street, Toronto M5S 3G4, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Weedbrook
authors.affiliation: School of Science and Technology, University of Camerino, Camerino, Macerata 62032, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Vitali
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Shapiro
authors.affiliation: Department of Computer Science and York Centre for Quantum Technologies, University of York, York YO10 5GH, United Kingdom.
authors.forename: Stefano
authors.initials: S
authors.lastname: Pirandola