Sequential generation of multiphoton entanglement with a Rydberg superatom

TL;DR

This paper demonstrates an efficient method to generate multiphoton entanglement using a Rydberg superatom, achieving entanglement of up to 12 photons with improved efficiency over previous techniques.

Contribution

The authors introduce a novel approach utilizing a Rydberg superatom for scalable, deterministic multiphoton entanglement generation, surpassing previous probabilistic methods.

Findings

Achieved entanglement of up to 12 photon modes.

Efficiency scaling factor for adding one photon is 0.27.

Method surpasses previous results in efficiency and scalability.

Abstract

Multiqubit entanglement is an indispensable resource for quantum information science. In particular, the entanglement of photons is of conceptual interest due to its implications in measurement-based quantum computing, communication, and metrology. The traditional way of spontaneous parametric down-conversion already demonstrates entanglement of up to a dozen photons but is hindered by its probabilistic nature. Here, we experimentally demonstrate an efficient approach for multi-photon generation with a Rydberg superatom, a mesoscopic atomic ensemble under Rydberg blockade. Using it as an efficient single-photon interface, we iterate the photon creation process that gives rise to a train of temporal photonic modes entangled in photon number degree. We detect the multiphoton entanglement via converting the photon number degree to a time-bin degree. Photon correlations verify entanglement up to 12 modes. The efficiency scaling factor for adding one photon is 0.27, surpassing previous results, and can be increased significantly without fundamental limitations.