The scheme of repeater graph states with quantum steering

Abstract Fidelity and rate of information (or the key rate in quantum key distribution (QKD)) decay exponentially with distance in long-distance quantum channels . The most common and well-known approach to address this fundamental problem is the so-called quantum repeater. We show how end nodes can participate in a repeater graph state (RGS) protocol link, and propose a steering repeater protocol. The protocol discusses the issue of clock synchronization between nodes and reduces the complexity of end node devices. We also employ measurement device independent (MDI) scheme to secure the repeater link. In addition, we show that the RGS protocol can transmit steering states, extending its applicability beyond quantum key distribution.