Integrated nanophotonic platform for on-chip quantum emitter interactions and entanglement

TL;DR

This paper presents a nanophotonic platform that enables enhanced long-range interactions and entanglement between solid-state quantum emitters on-chip, advancing scalable quantum photonic technologies.

Contribution

The authors introduce a novel integrated nanophotonic architecture that mediates controllable long-range quantum emitter interactions using engineered surface plasmon polaritons.

Findings

Demonstrated large enhancement of energy transfer rates.

Achieved suppression of energy transfer compared to bare substrates.

Predicted near-maximal transient entanglement between quantum emitters.

Abstract

Entanglement between solid-state quantum emitters (QEs) is a key resource for photonic quantum technologies. Achieving such entanglement requires strong and controllable long-range interactions between QEs. However, engineering such coupling remains challenging, particularly for on-chip distant solid-state QEs. Here, we introduce a forward-designed platform that enables ultracompact nanophotonic architectures to mediate enhanced long-range QE-QE interactions via engineered surface plasmon polariton interference. Using this strategy, we realize two distinct configurations: a phase-conjugated elliptic design for energy funneling, and a co-radiating hyperbolic design for its suppression. We experimentally demonstrate large enhancement and suppression of energy transfer rates compared to bare substrates. Furthermore, we predict transient entanglement between spatially separated QEs with concurrence peaking at 0.493, approaching the theoretical bound in the transient regime. Extending to the multi-QE case, we observe enhanced energy funneling and predict QE-QE entanglement in three-QE configurations. These results establish a compact and scalable framework for on-chip entanglement engineering in integrated quantum nanophotonic systems.