Performance of quantum networks over time-varying amplitude damping channels with repeater and multiple sending nodes

Abstract In this paper, we consider an efficient dual-hop quantum communication network with multiple senders or nodes, a repeater, and a receiver. We derive closed-form expressions for the system quantum outage probability (QOP) assuming time-varying amplitude damping (TVAD) quantum channels. In addition, closed-form expressions for the quantum hashing outage probability of two approximated quantum channels, namely TVAD Pauli twirl approximated (TVADPTA) and TVAD Clifford twirl approximated (TVADCTA) channels are also provided. These channels are efficient in modeling the simplest kind of noise in quantum devices. Opportunistic node scheduling is proposed, for the first time, to select among sending nodes, where the node of the largest relaxation time T 1 is allowed to transmit to repeater, which in turn communicates with receiver. The impact of various system parameters, including number of sending nodes K , coefficient of variation of relaxation time ϵ , code rates of both hops, channel damping parameter γ , and channel noise limit γ l ( R ) on the system performance is investigated. Findings show that for the case where first hop is dominating the system performance, the more the number of nodes, the better the achieved performance. This gain starts to vanish once the second hop starts dominating the system performance. For good quality channels, more nodes are needed in order for second hop to dominate the system performance compared to the case of low quality channels. Finally, results illustrate that for higher values of ϵ , and in order to achieve a certain target QOP, both nodes and repeater need to adapt their transmission rates to the optimum values.