Skyrmions are topological optical fields that hold great promise for encoding and manipulating quantum information. Here we report the first realisation of optical skyrmions across two wavelengths, where the skyrmion topology arises as a shared property between dual-wavelength entangled photons or on single photon states at either wavelength. Through a voltage-controlled spin-orbit device, we achieve a topology switching between non-local and local skyrmion topology while preserving the entanglement and topology in both cases. The dual-wavelength configuration allows the creation of skyrmion topology on a visible photon suitable for imaging or switching the local skyrmion topology to a telecom-band photon suitable for fiber communication. This work paves the way for topological quantum state engineering with applications in quantum communication, quantum imaging and heralded single-photon sources.
Skyrmions are topological optical fields that hold great promise for encoding and manipulating quantum information. Here we report the first realisation of optical skyrmions across two wavelengths, where the skyrmion topology arises as a shared property between dual-wavelength entangled photons or on single photon states at either wavelength. Through a voltage-controlled spin-orbit device, we achieve a topology switching between non-local and local skyrmion topology while preserving the entanglement and topology in both cases. The dual-wavelength configuration allows the creation of skyrmion topology on a visible photon suitable for imaging or switching the local skyrmion topology to a telecom-band photon suitable for fiber communication. This work paves the way for topological quantum state engineering with applications in quantum communication, quantum imaging and heralded single-photon sources.
We propose a spin-orbit strategy for generating dual-wavelength quantum skyrmions realized either as entangled photon pairs at dual wavelengths or as heralded single-photon states at a given wavelength-regimes neither previously conceptualized nor demonstrated. By coupling a two-photon entangled state to an electrically tunable liquid crystal topological defect, we engineer both nonlocal and local skyrmionic topologies in a reconfigurable platform. We highlight with examples how this approach may open new directions for engineered topological quantum states that exploit the topological richness of liquid crystals.
We propose a spin-orbit strategy for generating dual-wavelength quantum skyrmions, realized either as entangled photon pairs at dual wavelengths or as heralded single-photon states at a given wavelength -- regimes neither previously conceptualized nor demonstrated. By coupling a two-photon entangled state to an electrically tunable liquid crystal topological defect, we engineer both nonlocal and local skyrmionic topologies in a reconfigurable platform. We highlight with examples how this approach may open new directions for engineered topological quantum states that exploit the topological richness of liquid crystals.
Skyrmions are a particle-like topology with a quantised skyrmion number, realised across condensed matter and photonic platforms alike. In quantum photonics, they constitute an emerging resource, promising robust quantum information encoding, so far realised as single photon and bi-photon entangled states. Here we report the first visualisation of tripartite entanglement dynamics through topological structure using spin-skyrmion entangled states, where the topology of a single photon is remotely controlled through the spin of its entangled partner. We visualise our tripartite state theoretically by introducing the notion of a topological Bloch sphere that completely captures the entanglement and topolological features of the state. By leveraging this state, we realise the first quantum multiskyrmions, comprising multiple localised skyrmions within a single structure, that emulate signatures of their magnetic counterparts. We verify this experimentally and show that traversing our topological sphere reveals entanglement-driven particle-like motion of the localised topological structures. These dynamics unveil a physical manifestation of tripartite entanglement correlations which we illustrate by example of GHZ-like states, enabling a visualisation of multiple Bell states encoded within our system. Our work opens exciting possibilities for quantum sensing by mapping complex quantum channel features onto topological observables of multipartite states and offers a promising avenue for harnessing quantum topologies for multi-level encoding quantum communication schemes.
Quantum optical skyrmions, as topologically robust quantum information carriers, hold transformative potential for resilient high-dimensional quantum information networks. However, their practical exploitation was still restricted to a single quantum channel, which precludes the multiplexing essential for practical high-capacity quantum networks. Here, we utilize a metasurface to achieve multi-channel quantum state distribution of the polarization-entangled photon pairs, inducing a two-photon bunching effect in both the spin and spatial dimensions with compact flat optics. At the spatial bunching port, controlled manipulation of the spin-orbit interaction enables the generation of a tunable single-photon skyrmion pair. In contrast to any prior skyrmion generation, the single-photon skyrmions are mediated and topologically controlled by quantum measurement in multiple channels. Concurrently, during the amplitude and phase modulation process, both the skyrmion localization and the texture helicity can be precisely customized. The proposed tunable single-photon skyromions offer multidimensional controllability and topological stability provide a viable path toward noise-resilient high-dimensional quantum information processing.
Skyrmions, topologically stable field configurations, have recently emerged in classical optics as structured light for high-density data applications. Achieving controllable on-chip generation of single-photon skyrmions, while being highly desirable for quantum information technologies, remains challenging due to the nanoscale confinement of quantum emitters (QEs). Here we demonstrate a metasurface-integrated quantum emitter (metaQE) platform enabling room-temperature on-chip generation of single-photon skyrmions. Near-field coupling between QEs and propitiously designed surface arrays of meta-atoms mediates spin-orbit interaction, transforming nanoscale-localized dipole emission into free-propagating topologically structured photonic modes. By exploiting this approach for structuring quantum emission from different color centers in nanodiamonds, we realize diverse skyrmionic states, including high-order anti-skyrmions and skyrmionium, and thereby demonstrate its universality across QEs. Our work establishes a unified framework for on-chip structured quantum light sources, offering versatile control of high-dimensional topological states, such as skyrmions, and advancing scalable quantum photonic technologies.
Abstract Quantum skyrmions as topologically structured quantum photonic states are promising candidates for enabling robust quantum information processing in real-world environments where entanglement is fragile. The state-of-the-art allows their creation as single photon and entangled states, but their storage in a quantum memory is crucial to realise real applications, e.g., quantum repeaters for quantum networks as well as gates and synchronisation for quantum computers. Here we demonstrate the first entanglement mediated quantum memory of quantum skyrmions in cold atomic ensembles. To achieve this, we produce the first narrow-band quantum skyrmions from spontaneous four‑wave mixing, yielding a sub‑natural linewidth compatible with atomic transitions. We then store the spatially encoded photon (one of the entangled pair) in an electromagnetically induced transparency memory, subjecting it to light‑matter interaction and decoherence while its entangled partner remains free, thus demonstrating the first storage and retrieval of quantum topology. Crucially, we observe that the Skyrme number remains resilient even as entanglement decays under storage noise, demonstrating the inherent topological robustness of the non‑local state. Our work establishes cold atomic ensembles as an integrated platform for quantum topological photonics, combining narrowband entanglement generation, reconfigurable topological engineering, and coherent quantum storage. These results bridge structured light, quantum information, and topological physics, and open pathways toward topologically protected quantum repeaters and noise-resilient quantum networks, where topology itself acts as a resource for preserving quantum information.