Entanglement represents ``\textit{the}'' key resource for several applications of quantum information processing, ranging from quantum communications to distributed quantum computing. Despite its fundamental importance, deterministic generation of maximally entangled qubits represents an on-going open problem. Here, we design a novel generation scheme exhibiting two attractive features, namely, i) deterministically generating different classes -- namely, GHZ-like, W-like and graph states -- of genuinely multipartite entangled states, ii) without requiring any direct interaction between the qubits. Indeed, the only necessary condition is the possibility of coherently controlling -- according to the indefinite causal order framework -- the causal order among the unitaries acting on the qubits. Through the paper, we analyze and derive the conditions on the unitaries for deterministic generation, and we provide examples for unitaries practical implementation. We conclude the paper by discussing the scalability of the proposed scheme to higher dimensional genuine multipartite entanglement (GME) states and by introducing some possible applications of the proposal for quantum networks.

翻译：纠缠是量子信息处理（从量子通信到分布式量子计算）中多个应用的关键资源。尽管其具有根本重要性，但最大纠缠量子比特的确定性生成仍是一个持续存在的开放问题。在此，我们设计了一种新颖的生成方案，该方案具有两个吸引人的特性：i）能够确定性地生成不同类别的真正多方纠缠态——即类GHZ态、类W态和图态；ii）无需量子比特之间的任何直接相互作用。事实上，唯一必要的条件是能够根据不定因果顺序框架对作用于量子比特的幺正操作之间的因果顺序进行相干控制。在本文中，我们分析并推导了用于确定性生成的幺正操作条件，并提供了幺正操作实际实现的示例。最后，我们讨论了所提方案向更高维真正多方纠缠（GME）态的可扩展性，并介绍了该方案在量子网络中的一些可能应用。