• DOI:10.1103/PhysRevLett.127.040504
• Corpus ID: 236429038

Experimental Quantum Target Detection Approaching the Fundamental Helstrom Limit.

@article{Xu2021ExperimentalQT,
  title={Experimental Quantum Target Detection Approaching the Fundamental Helstrom Limit.},
  author={Feixiang Xu and Xiao-Ming Zhang and Liang Xu and Tao Jiang and Man-Hong Yung and Lijian Zhang},
  journal={Physical review letters},
  year={2021},
  volume={127 4},
  pages={
          040504
        }
}

• Feixiang Xu, Xiao-Ming Zhang, +3 authors Lijian Zhang
• Published 23 July 2021
• Physics
• Physical review letters

Quantum target detection is an emerging application that utilizes entanglement to enhance the sensing of the presence of an object. Although several experimental demonstrations for certain situations have been reported recently, the single-shot detection limit imposed by the Helstrom limit has not been reached because of the unknown optimum measurements. Here we report an experimental demonstration of quantum target detection, also known as quantum illumination, in the single-photon limit. In our experiment, one photon of the maximally entangled photon pair is employed as the probe signal and the corresponding optimum measurement is implemented at the receiver. We explore the detection problem in different regions of the parameter space and verify that the quantum advantage exists even in a forbidden region of the conventional illumination, where all classical schemes become useless. Our results indicate that quantum illumination breaks the classical limit for up to 40%, while approaching the quantum limit imposed by the Helstrom limit. These results not only demonstrate the advantage of quantum illumination, but also manifest its valuable potential of target detection.