Enhanced Optimal Quantum Communication by Generalized Phase Shift Keying Coherent Signal

Abstract

It is well known that the maximal success probability of the binary quantum communication can be improved by using a sub-Poissonian non-standard coherent state as an information carrier. In the present article, we consider the quantum communication with $N$-ary phase shift keying ($N$-PSK) signal for an arbitrary positive integer $N>1$. By using non-standard coherent state, we analytically provide the maximal success probability of the quantum communication with $N$-PSK. Unlike the binary case, we show that even super-Poissonianity of non-standard coherent state can improve the maximal success probability of $N$-PSK quantum communication.