Quantum teleportation enables high-security communications through end-to-end quantum entangled pairs. End-to-end entangled pairs are created by using swapping processes to consume short entangled pairs and generate long pairs. However, due to environmental interference, entangled pairs decohere over time, resulting in low fidelity. Thus, generating entangled pairs at the right time is crucial. Moreover, the swapping process also causes additional fidelity loss. To this end, this paper presents a short time slot protocol, where a time slot can only accommodate a process. It has a more flexible arrangement of entangling and swapping processes than the traditional long time slot protocol. It raises a new optimization problem TETRIS for finding strategies of entangling and swapping for each request to maximize the fidelity sum of all accepted requests. To solve the TETRIS, we design two novel algorithms with different optimization techniques. Finally, the simulation results manifest that our algorithms can outperform the existing methods by up to 60 ~ 78% in general, and by 20 ~ 75% even under low entangling probabilities.

翻译：量子隐形传态通过端到端的量子纠缠对实现高安全性通信。端到端的纠缠对通过消耗短距离纠缠对并生成长距离纠缠对的交换过程来建立。然而，由于环境干扰，纠缠对会随时间发生退相干，导致保真度降低。因此，在恰当的时间生成纠缠对至关重要。此外，交换过程也会造成额外的保真度损失。为此，本文提出一种短时隙协议，每个时隙仅容纳一个过程。相较于传统的长时隙协议，该协议能更灵活地安排纠缠生成与交换过程。这引出了一个名为TETRIS的新优化问题，旨在为每个请求寻找纠缠与交换策略，以最大化所有被接受请求的保真度总和。为解决TETRIS问题，我们设计了两种采用不同优化技术的新算法。最终，仿真结果表明，我们的算法在一般情况下性能优于现有方法达60%~78%，即使在低纠缠概率下也能提升20%~75%。