Long-range dipole-dipole interactions (DDIs) are essential for enabling scalable quantum technologies. However, their practical realization is fundamentally limited by spatial rapid decay and environmental noise. In this study, we propose a plasmon-assisted microcavities platform that integrates a photonic cavity with a plasmonic antenna for enhanced energy transfer between donors and acceptors. Benefiting from the resonating of the acceptors within the microcavity after receiving energy, stable long-range DDIs with an interaction distance of ∼13.6 μm and lasing emission can be achieved at ambient temperature. The results of this study suggest the potential for long-range, efficient DDIs in on-chip quantum systems with potential applications in quantum sensing and energy harvesting.
Long-range dipole-dipole interactions (DDIs) are essential for enabling scalable quantum technologies. However, their practical realization is fundamentally limited by spatial rapid decay and environmental noise. In this study, we propose a plasmon-assisted microcavities platform that integrates a photonic cavity with a plasmonic antenna for enhanced energy transfer between donors and acceptors. Benefiting from the resonating of the acceptors within the microcavity after receiving energy, stable long-range DDIs with an interaction distance of ∼13.6 μm and lasing emission can be achieved at ambient temperature. The results of this study suggest the potential for long-range, efficient DDIs in on-chip quantum systems with potential applications in quantum sensing and energy harvesting.
) exhibit sharp 4f-4f transitions that are highly sensitive to dipole-dipole interactions (DDIs), yet the intrinsic short-range of DDIs restricts their application in long-distance quantum coupling. Here, we demonstrate a plasmonic nanocavity pair that simultaneously couples to upconversion nanoparticles (UCNPs) and quantum dots (QDs), enabling enhanced emission and inter-emitter interaction. The combined effects of Purcell enhancement and surface plasmon polariton (SPP) propagation extend the DDI-mediated energy transfer over a record distance exceeding 7.5 μm, 2 orders of magnitude longer than conventional Förster resonance systems. Moreover, the polarization-controlled SPP propagation directs the in-plane energy redistribution, achieving anisotropic and tunable coupling. This work establishes a viable route toward controllable, long-range DDIs among rare-earth emitters, advancing integrated quantum photonic architectures.
Plasmonic nanocavities enable the synchronization of spatially distant emissive dipoles through strong near-field coupling in sub-nm gaps. We report formation of a room-temperature synchronized dipole state in locally-ordered plasmonic nanogap 2D arrays under non-resonant continuous-wave pumping. Unlike lasers, photonic Bose-Einstein condensates, or exciton-polariton condensates, this system exhibits spatial coherence across the dipoles, while rapid radiative and non-radiative emission suppresses temporal photon coherence. A change of behaviour is observed with increasing pumping, marked by the spatial spread of g^((1)) coherence, but without spectral narrowing or directional emission. This driven-dissipative system exhibits fast temporal coherence decay and complex spatial correlations, offering a new platform for studying synchronization at room temperature. Combining ultralow mode volumes, high Purcell enhancement, and scalable ambient operation, it opens pathways for novel photonic and quantum technologies.
Plasmonic nanocavities enable the synchronization of spatially distant emissive dipoles through strong near-field coupling in sub-nm gaps. We report formation of a room-temperature synchronized dipole state in locally-ordered plasmonic nanogap 2D arrays under non-resonant continuous-wave pumping. Unlike lasers, photonic Bose-Einstein condensates, or exciton-polariton condensates, this system exhibits spatial coherence across the dipoles, while rapid radiative and non-radiative emission suppresses temporal photon coherence. A change of behaviour is observed with increasing pumping, marked by the spatial spread of g(1) coherence, but without spectral narrowing or directional emission. This driven-dissipative system exhibits fast temporal coherence decay and complex spatial correlations, offering a new platform for studying synchronization at room temperature. Combining ultralow mode volumes, high Purcell enhancement, and scalable ambient operation, it opens pathways for novel photonic and quantum technologies.
We explore the entanglement generation between two dipole emitters via a hybrid photonic-plasmonic resonant structure which consists of two metal nanoparticles (MNPs) and a high-Q whispering-gallery-mode (WGM) microcavity. Because the coupling strength between the dipole emitter and the cavity can be substantially enhanced with the help of MNPs and maintained by the WGM cavity, the maximum entanglement plateau between two dipole emitters can be deterministically created even in the presence of the spontaneous emission of the dipole emitters and the decay induced by the microcavity and MNPs. The width of the plateau depends on the coupling strengths (or the radii of the MNPs) and the initial state, but is insensitive to the dipole-cavity detuning. These results are useful in real experiments.
The resonance energy transfer and entanglement between two-level quantum emitters are typically limited to sub-wavelength distances due to the inherently short-range nature of the dipole-dipole interactions. Moreover, the entanglement of quantum systems is hard to preserve for a long time period due to decoherence and dephasing mainly caused by radiative and nonradiative losses. In this work, we outperform the aforementioned limitations by presenting efficient long-range inter-emitter entanglement and large enhancement of resonance energy transfer between two optical qubits mediated by epsilon-near-zero (ENZ) and other plasmonic waveguide types, such as V-shaped grooves and cylindrical nanorods. More importantly, we explicitly demonstrate that the ENZ waveguide resonant energy transfer and entanglement performance drastically outperforms the other waveguide systems. Only the excited ENZ mode has an infinite phase velocity combined with a strong and homogeneous electric field distribution, which leads to a giant energy transfer and efficient entanglement independent of the emitters' separation distances and nanoscale positions in the ENZ nanowaveguide, an advantageous feature that can potentially accommodate multi-qubit entanglement. Moreover, the transient entanglement can be further improved and become almost independent of the detrimental decoherence effect when an optically active (gain) medium is embedded inside the ENZ waveguide. We also present that efficient steady-state entanglement can be achieved by using a coherent external pumping scheme. Finally, we report a practical way to detect the steady-state entanglement by computing the second-order correlation function. The presented findings stress the importance of plasmonic ENZ waveguides in the design of the envisioned on-chip quantum communication and information processing plasmonic nanodevices.
Abstract Quantum antennas couple localized quantum emitters to optical modes that can be collected, routed, and used in larger photonic systems. Their performance depends on photon delivery as well as single-photon purity, coherence, and indistinguishability. This Review connects the physics of light-matter interaction with the design of quantum-photonic interfaces. We compare semiconductor quantum dots, color centers, two-dimensional and molecular emitters, and examine plasmonic, dielectric, hybrid, cavity-coupled, and waveguideintegrated antenna architectures. We discuss how emitter position, dipole orientation, spectral matching, and material loss govern radiative enhancement and quenching, then assess performance through efficiency, brightness, photon statistics, and coupling to useful optical modes. Electromagnetic and quantum-optical modeling are considered alongside fabrication, deterministic emitter placement, and experimental characterization. We further examine how arrays and metasurfaces extend control to collective emission and quantum wavefronts, and survey applications in single-photon generation, communication, networking, computing, sensing, imaging, and ranging. Across these settings, rapid decay and strong local fields produce system-level gains only when useful photon delivery improves without compromising quantum-state quality. Low-loss design, spectral stabilization, reproducible integration, and complete photon-budget reporting emerge as priorities for scalable quantum-antenna platforms.