Much recent work on distributed quantum computing have focused on the use of entangled pairs and distributed two qubit gates. But there has also been work on efficient schemes for achieving multipartite entanglement between nodes in a single shot, removing the need to generate multipartite entangled states using many entangled pairs. This paper looks at how multipartite entanglement resources (e.g., GHZ states) can be useful for distributed fan-out operations; we also consider the use of qudits of dimension four for distributed quantum circuit compression. In particular, we consider how such fan-out operations and qudits can be used to implement circuits which are challenging for distributed quantum computation, involving pairwise qubit interactions, i.e., what has been called global gates (a.k.a. global Mølmer-Sørensen gates). Such gates have been explored to possibly yield more efficient computations via reduced circuit depth, and can be carried out efficiently in some types of quantum hardware (e.g., trapped-ion quantum computers); we consider this as an exploration of an ``extreme'' case for distribution given the global qubit-qubit interactions. We also conclude with some implications for future work on quantum circuit compilation and quantum data centre design.

翻译：近期关于分布式量子计算的研究多集中于纠缠对与分布式双量子比特门的应用。然而，也有研究工作致力于开发单次实现节点间多体纠缠的高效方案，从而避免使用大量纠缠对生成多体纠缠态。本文探讨多体纠缠资源（如GHZ态）如何有效支持分布式扇出操作；同时研究四维高维量子比特在分布式量子电路压缩中的应用。特别地，我们分析此类扇出操作与高维量子比特如何实现分布式量子计算中具有挑战性的电路——涉及成对量子比特相互作用，即所谓全局门（亦称全局Mølmer-Sørensen门）。这类门通过降低电路深度可能实现更高效计算，且可在某些量子硬件（如囚禁离子量子计算机）中高效执行；鉴于其全局量子比特-量子比特相互作用特性，本研究可视为分布式场景下的一种"极端"案例探索。最后，我们总结了本研究对未来量子电路编译与量子数据中心设计工作的启示。