We introduce a novel light-matter interface that integrates a nanoscale buried heterostructure emitter into a dielectric bowtie cavity, co-localising the optical hotspot and the electronic wavefunction. This platform enables strong light-matter interaction through deep subwavelength confinement while remaining compatible with scalable fabrication. We show that in this regime an explicit treatment of the emitter's spatial extent is required, and that a confinement-factor approximation more accurately predicts the coupling, revealing design rules inaccessible to dipole-based metrics. For an InP/InGaAsP system, we predict coupling strengths of 0.4-0.7 meV for gap sizes of 50-10 nm, establishing the buried heterostructure-bowtie architecture as a practical route to deterministic strong coupling in solid-state nanophotonics.
We introduce a novel light-matter interface that integrates a nanoscale buried heterostructure emitter into a dielectric bowtie cavity, co-localising the optical hotspot and the electronic wavefunction. This platform enables strong light-matter interaction through deep subwavelength confinement while remaining compatible with scalable fabrication. We show that in this regime an explicit treatment of the emitter's spatial extent is required, and that a confinement-factor approximation more accurately predicts the coupling, revealing design rules inaccessible to dipole-based metrics. For an InP/InGaAsP system, we predict coupling strengths of 0.4-0.7 meV for gap sizes of 50-10 nm, establishing the buried heterostructure-bowtie architecture as a practical route to deterministic strong coupling in solid-state nanophotonics.
The deterministic control of light-matter interactions at the level of single particles and on subwavelength scales is central to quantum optics and hybrid integrated quantum technologies. However, combining cold atom research with nanophotonic devices in a fully controllable platform remains a major experimental challenge. Here, we demonstrate the deterministic coupling of an ultracold atomic lattice to light propagating in suspended on-chip photonic circuits. These capabilities open avenues to address scalability challenges in neutral-atom quantum computers and simulators, enabling fast optical readout, efficient and subwavelength non-diffracting interaction zones, and genuine compatibility with integrated solid-state photon sources, detectors, and stop-band modulators. Beyond controllable quantum matter, the platform also enables in-situ imaging of evanescent fields of light and nanoscale structures, including prospects for three-dimensional scanning microscopy with non-invasive single-atom probes for quantum sensing applications.
The realization of deterministic photon–photon gates is a central goal in optical quantum computation and engineering. A longstanding challenge is that optical nonlinearities in scalable, room-temperature material platforms are too weak to achieve the required strong coupling, due to the critical loss-confinement trade-off in existing photonic structures. In this work, we introduce a spatio-temporal confinement method, dispersion-engineered temporal trapping, to circumvent the trade-off, enabling a route to all-optical strong coupling. Temporal confinement is imposed by an auxiliary trap pulse via cross-phase modulation, which, combined with the spatial confinement of a waveguide, creates a “flying cavity” that enhances the nonlinear interaction strength by at least an order of magnitude. Numerical simulations confirm that temporal trapping confines the multimode nonlinear dynamics to a single-mode subspace, enabling high-fidelity deterministic quantum gate operations. With realistic dispersion engineering and loss figures, we show that temporally trapped ultrashort pulses could achieve strong coupling on near-term nonlinear nanophotonic platforms. Our results highlight the potential of ultrafast nonlinear optics to become the first scalable, high-bandwidth, and room-temperature platform that achieves strong coupling, opening a path to quantum computing, simulation, and light sources.
High Resolution Image Download MS PowerPoint Slide Spin-dependent, directional light–matter interactions form the basis of chiral quantum networks. In the solid state, quantum emitters commonly possess circularly polarized optical transitions with spin-dependent handedness. We demonstrate numerically that spin-dependent chiral coupling can be realized by embedding such an emitter in a waveguide-coupled nanocavity, which supports two near-degenerate, orthogonally polarized cavity modes. The chiral behavior arises due to direction-dependent interference between the cavity modes upon coupling to two single-mode output waveguides. Notably, an experimentally realistic cavity design simultaneously supports near-unity chiral contrast, efficient (>95%) cavity-waveguide coupling and enhanced light–matter interaction strength (Purcell factor F P > 70). In combination, these parameters enable the development of highly coherent spin–photon interfaces ready for integration into nanophotonic circuits.
By embedding a single quantum emitter inside a nanoresonator that strongly localizes optical field, it is possible to achieve a very strong light-matter interaction. The strength of this interaction is characterized by the coherent emitter-field coupling strength (g), which increases with reduction in the optical mode volume and which also sets the limit on the operational speed of such a system. With InAs quantum dots inside GaAs photonic crystal cavities, coupling strengths of 40 GHz can be reached (much greater than the record values in atom-cavity QED systems), while nanometallic cavities could increase them over 100 GHz, as a result of the further reduction in the mode volume. Such a quantum dot-nanocavity platform is of interest for various quantum technologies, as well as in optical switching/computing.
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.
Abstract One important building block for future integrated nanophotonic devices is the scalable on-chip interfacing of single photon emitters and quantum memories with single optical modes. Here we present the deterministic integration of a single solid-state qubit, the nitrogen-vacancy (NV) center, with a photonic platform consisting exclusively of SiO2 grown thermally on a Si substrate. The platform stands out by its ultra-low fluorescence and the ability to produce various passive structures such as high-Q microresonators and mode-size converters. By numerical analysis an optimal structure for the efficient coupling of a dipole emitter to the guided mode could be determined. Experimentally, the integration of a preselected NV emitter was performed with an atomic force microscope and the on-chip excitation of the quantum emitter as well as the coupling of single photons to the guided mode of the integrated structure could be demonstrated. Our approach shows the potential of this platform as a robust nanoscale interface of on-chip photonic structures with solid-state qubits.