Huet H, Ramesh P R, Wein S C, Coste N, Hilaire P, Somaschi N, Morassi M, Lemaître A, Sagnes I, Doty M F, Krebs O, Lanco L, Fioretto D A, Senellart P
Centre de Nanosciences et de Nanotechnologies, Université Paris-Saclay, Palaiseau, France.
University of Delaware, Newark, USA.
Nat Commun. 2025 May 9;16(1):4337. doi: 10.1038/s41467-025-59693-3.
Measurement-based quantum computing offers a promising route towards scalable, universal photonic quantum computation. This approach relies on the deterministic and efficient generation of photonic graph states in which many photons are mutually entangled with various topologies. Recently, deterministic sources of graph states have been demonstrated with quantum emitters in both the optical and microwave domains. In this work, we demonstrate deterministic and reconfigurable graph state generation with optical solid-state integrated quantum emitters. Specifically, we use a single semiconductor quantum dot in a cavity to generate caterpillar graph states, the most general type of graph state that can be produced with a single emitter. By using fast detuned optical pulses, we achieve full control over the spin state, enabling us to vary the entanglement topology at will. We perform quantum state tomography of two successive photons, measuring Bell state fidelities up to 0.80 ± 0.04 and concurrences up to 0.69 ± 0.09, while maintaining high photon indistinguishability. This simple optical scheme, compatible with commercially available quantum dot-based single photon sources, brings us a step closer to fault-tolerant quantum computing with spins and photons.
基于测量的量子计算为实现可扩展的通用光子量子计算提供了一条很有前景的途径。这种方法依赖于确定性且高效地生成光子图态，其中许多光子以各种拓扑结构相互纠缠。最近，在光学和微波领域，利用量子发射体已经演示了图态的确定性源。在这项工作中，我们展示了利用光学固态集成量子发射体实现确定性和可重构的图态生成。具体而言，我们使用腔中的单个半导体量子点来生成毛毛虫图态，这是能用单个发射体产生的最一般类型的图态。通过使用快速失谐光脉冲，我们实现了对自旋态的完全控制，使我们能够随意改变纠缠拓扑结构。我们对两个连续光子进行量子态层析成像，测量到的贝尔态保真度高达0.80±0.04，并发度高达0.69±0.09，同时保持了高光子不可区分性。这种简单的光学方案与市售的基于量子点的单光子源兼容，使我们向基于自旋和光子的容错量子计算又迈进了一步。
