Indirect Measurement for Optimal Quantum Communication Enhanced by Binary Non-standard Coherent States

Enhanced Optimal Quantum Communication by Generalized Phase Shift Keying Coherent Signal

“…By using NS-CS, we have analytically provided the Helstrom bound of the quantum communication with N -PSK. Unlike the binary case [11,12], we have shown that even super-Poissonianity of NS-CS can improve the Helstrom bound of N -PSK quantum communication: The Helstrom bound can be improved by considering the sub-Poissonian NS-CS for N = 3, meanwhile the super-Poissonian NS-CS can improve the Helstrom bound for N = 4 and N = 8.…”

“…4(c), each minimum error probabilty of 8-NSPSK signal composed of P-CS is smaller than that of 8-SPSK signal for arbitrary mean photon number. This result is rather surprising since even super-Poissonianity in P-CS can enhance the 4-PSK and 8-PSK quantum communication unlike the binary case [12]. We discuss the details in the next section.…”

“…* freddie1@khu.ac.kr According to a recent work [11], the maximal success probability (or Helstrom bound) of discriminating a message encoded in 2-PSK signal composed of nonstandard coherent states (NS-CS) with a novel quantum measurement can be improved by the sub-Poissonianity of the NS-CS. Moreover, the experimental method for implementing the quantum measurement reaching for the Helstrom bound has recently been proposed [12]. Since the negative Mandel parameter to quantify the sub-Poissonianity is considered as a resource in a non-classical light [13], this result implies that the sub-Poissonianity can be a resource for improving the performance of the quantum communication.…”