Experimental ten-photon entanglement

TL;DR

This paper reports the first demonstration of genuine ten-photon entanglement using a high-brightness spontaneous parametric down-conversion source, advancing multi-photon quantum experiments and applications.

Contribution

It introduces a high-brightness, efficient photon source enabling the creation of ten-photon entanglement, surpassing previous multi-photon entanglement benchmarks.

Findings

Successfully generated ten-photon entanglement with high fidelity.

Achieved a collection efficiency of ~70% and indistinguishability of ~91%.

Demonstrated potential for scalable quantum information processing.

Abstract

Quantum entanglement among multiple spatially separated particles is of fundamental interest, and can serve as central resources for studies in quantum nonlocality, quantum-to-classical transition, quantum error correction, and quantum simulation. The ability of generating an increasing number of entangled particles is an important benchmark for quantum information processing. The largest entangled states were previously created with fourteen trapped ions, eight photons, and five superconducting qubits. Here, based on spontaneous parametric down-converted two-photon entanglement source with simultaneously a high brightness of ~12 MHz/W, a collection efficiency of ~70% and an indistinguishability of ~91% between independent photons, we demonstrate, for the first time, genuine and distillable entanglement of ten single photons under different pump power. Our work creates a state-of-the-art platform for multi-photon experiments, and provide enabling technologies for challenging optical quantum information tasks such as high-efficiency scattershot boson sampling with many photons.