Quantum - enhanced change detection and joint communication - detection

Total: 1

The rapid recognition of transmission changes in the optical channel is crucial for secure communication. We show that the pre-divided interlocking using two-mode-squeeze vacuum states significantly reduces the recognition latency compared to classic and interlocked probes for coherent states. The change recognition latency is inversely proportional to the relative quantum tropy (QRE), which goes against infinity without thermal noise, which indicates an idealized immediate recognition. In realistic scenarios, however, we show that QRE scales logarithmically with the reciprocal of the mean photon number of thermal noise. We propose a recipient who achieves this scaling and quantify his performance gains compared to existing methods. In addition, we examine the basic compromise between communication capacity and latency in change recognition and highlight how the pre-divided restriction both improves.