Entanglement Distribution

Dieter Jaksch

Wenhan Dai, Tianyi Peng, Moe Z. Win

Entanglement swapping enables entanglement distribution between distant nodes in quantum networks. This paper aims at designing remote entanglement distribution (RED) protocols to schedule entanglement swapping for maximizing the entanglement distribution rate (EDR). The concept of Enodes is introduced to represent the entangled quantum bit pairs in the network. With such a concept, we can transform the design of the optimal RED protocols into solving certain linear programming problems. In addition, we study RED in the homogeneous repeater chain, which is a basic and critical quantum network. Specifically, we determine the closed-form expression for the maximum EDR in such a setting. Our results will enable the distribution of long-distance entanglement with noisy intermediate-scale quantum (NISQ) technologies.

Zirui Xiao, Jian Li, Kaiping Xue +4 more

Remote entanglement distribution plays a crucial role in quantum networks, which can support many essential and exciting quantum applications. As the network scale expands, it is urgent to design a general and efficient remote entanglement distribution protocol. Nowadays, connection-oriented remote entanglement distribution protocols are available to achieve reliable entanglement distribution. However, in memory-limited quantum networks, connection-oriented entanglement distribution protocols cannot utilize entanglement resources fully and increase the delay of End-to-End (E2E) entanglement connection establishment. To overcome these shortcomings of existing entanglement distribution protocols, we design a connectionless remote entanglement distribution protocol to let Source-Destination (S-D) pairs compete for entanglement resources simultaneously. In our protocol, a fair request scheduling algorithm is proposed to reduce the waiting time without entanglement connections between S-D pairs. Furthermore, a fast scheduling trigger mechanism is proposed to perform entanglement swapping timely to reduce the delay of E2E entanglement connection establishment. The simulation results show that the designed protocol has advantages in terms of resource utilization, throughput, the service completion time of S-D pairs, and the maximum waiting time, compared with the existing remote entanglement distribution protocol.

Wenhan Dai, Tianyi Peng, Moe Z. Win

Distributing entanglement between distant nodes is an essential task in quantum networks. To achieve this task, quantum repeaters have been introduced to perform entanglement swapping. This paper offers a design of remote entanglement distribution (RED) protocols that maximize the entanglement distribution rate (EDR). We introduce the concept of enodes, representing the entangled quantum bit (qubit) pairs in the network. This concept enables us to design the optimal RED protocols based on the solutions of some linear programming problems. Moreover, we investigate RED in a homogeneous repeater chain, which is a building block for many quantum networks. In particular, we determine the maximum EDR for homogeneous repeater chains in a closed form. Our results enable the distribution of long-distance entanglement with noisy intermediate-scale quantum (NISQ) technologies and provide insights into the design and implementation of general quantum networks.

Matteo Villa