Quantum illumination with definite photon-number entangled states

Quantum illumination employs entangled states to detect aweakly reflecting target in a thermal bath. The performance of a given entangled state is evaluated from the minimum error probability in the asymptotic limit, which is compared against the optimal coherent state scheme. Using a relationship between the minimum error probability and quantum Fisher information, we compare the optimal performance of definite photon-number entangled states against that of coherent states under local repetitive strategies. When optimized under the constraint of a fixed total energy, we find that a coherent state outperforms the definite photon-number entangled states with the same signal energy. (C) 2022 Optica Publishing Group

Automated summary

This passage introduces the principles of quantum illumination and the method for evaluating its performance. It compares the performance of coherent states and entangled states in detecting weak signals.