Microwave quantum illumination using a digital receiver

• DOI: 10.1126/sciadv.abb0451
• Publication Date: 2020-05-08T23:15:37Z
• Authors: S. Barzanjeh; S. Pirandola; D. Vitali; J. M. Fink
• Keywords: Quantum sensor; SIGNAL (programming language)

Quantum illumination uses entangled signal-idler photon pairs to boost the detection efficiency of low-reflectivity objects in environments with bright thermal noise. Its advantage is particularly evident at low signal powers, a promising feature for applications such as noninvasive biomedical scanning or low-power short-range radar. Here, we experimentally investigate concept quantum microwave frequencies. We generate fields illuminate room-temperature object distance 1 m free-space setup. implement digital phase-conjugate receiver based on linear quadrature measurements that outperforms symmetric classical noise radar same conditions, despite entanglement-breaking path. Starting from experimental data, also simulate case perfect idler number detection, which results compared relative benchmark. Our highlight opportunities and challenges way toward first application circuits.