An open challenge in the context of quantum information processing and communication is improving the robustness of quantum information to environmental contributions of noise, a severe hindrance in real-world scenarios. Here, we show that quantum skyrmions and their nonlocal topological observables remain resilient to noise even as typical entanglement witnesses and measures of the state decay. This allows us to introduce the notion of digitization of quantum information based on our discrete topological quantum observables, foregoing the need for robustness of entanglement. We compliment our experiments with a full theoretical treatment that unlocks the quantum mechanisms behind the topological behavior, explaining why the topology leads to robustness. Our approach holds exciting promise for intrinsic quantum information resilience through topology, highly applicable to real-world systems such as global quantum networks and noisy quantum computers. Recent work reported a non-local quantum entangled state of photons with skyrmionic topology. Here the authors demonstrate theoretically and experimentally that topological properties of this system are resilient to noise, even as entanglement measures decay, and elucidate the mechanisms behind this robustness.
An open challenge in the context of quantum information processing and communication is improving the robustness of quantum information to environmental contributions of noise, a severe hindrance in real-world scenarios. Here, we show that quantum skyrmions and their nonlocal topological observables remain resilient to noise even as typical entanglement witnesses and measures of the state decay. This allows us to introduce the notion of digitization of quantum information based on our discrete topological quantum observables, foregoing the need for robustness of entanglement. We compliment our experiments with a full theoretical treatment that unlocks the quantum mechanisms behind the topological behavior, explaining why the topology leads to robustness. Our approach holds exciting promise for intrinsic quantum information resilience through topology, highly applicable to real-world systems such as global quantum networks and noisy quantum computers. Recent work reported a non-local quantum entangled state of photons with skyrmionic topology. Here the authors demonstrate theoretically and experimentally that topological properties of this system are resilient to noise, even as entanglement measures decay, and elucidate the mechanisms behind this robustness.
The topology of a pure state of two entangled photons is leveraged to provide a discretization of quantum information. Since discrete signals are inherently more resilient to the effects of perturbations, this discrete class of entanglement observables may offer an advantage against noise. Establishing this is the primary objective of this paper. We develop a noise model that exploits the specific form of such topological wave functions - an entangled state of two photons with one in an orbital angular momentum state and the other in a polarization state. We show that noise affecting both photons can be recast as a position-dependent perturbation affecting only the photon in the polarization state. This approach allows us to utilize both the language and concepts used in studying noisy qubits, as well as recent advances in quantum polarimetry. By adding noise to a finite-dimensional Hilbert space of polarization states, we can describe the noise using quantum operations expressed through appropriate Krauss operators, whose structure is determined by quantum polarimetry. For non-depolarizing noise, we provide an argument based on homotopic maps that demonstrates the topology's resilience to noise. For depolarizing noise, numerical studies using the quantum channel description show that the discrete entanglement signal remains completely resilient. Finally, we identify sources of local noise that can destabilize the topology. This foundational work establishes a framework for understanding how topology enhances the resilience of quantum information, directly impacting the distribution of information through entanglement in noisy environments, such as quantum computers and quantum networks.
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.
Quantum skyrmions as topologically structured entangled states have the potential to be a pathway toward robustness against external perturbations, but so far no theoretical framework exists to validate this. Here, we introduce the notion of a new entanglement observable based on such topologies and develop a theoretical framework for studying its evolution in general quantum channels. Using photons entangled in orbital angular momentum and polarization as an example, we show that the noise affecting both photons can be recast as a position-dependent perturbation affecting only the photon in the polarization state, restricting the noise to a finite-dimensional Hilbert space. From this we predict complete resilience for both non-depolarizing and depolarizing noise, the former by rigorous arguments based on homotopic maps and the latter by numerical simulation. Finally, we identify sources of local noise that can destabilize the topology and suggest why this may be ignored in practical situations. Our work sets a solid foundational framework for understanding how and why topology enhances the resilience of such entanglement observables, with immediate relevance to the distribution of information through entanglement in noisy environments, such as quantum computers and quantum networks.
Abstract The degradation of classical and quantum structured light induced by complex media constitutes a critical barrier to its practical implementation in a range of applications, from communication and energy transport to imaging and sensing. Atmospheric turbulence is an exemplary case due to its complex phase structure and dynamic variations, driving the need to fnd invariances in light. Here we construct classical and quantum optical skyrmions and pass them through experimentally simulated atmospheric turbulence, revealing the embedded topological resilience of their structure. In the quantum realm, we show that while skyrmions undergo diminished entanglement, their topological characteristics maintain stable. This is paralleled classically, where the vectorial structure is scrambled by the medium yet the skyrmion remains stable by virtue of its intrinsic topological protection mechanism. Our experimental results are supported by rigorous analytical and numerical modelling, validating that the quantum-classical equivalence of the topological behaviour is due to the non-separability of the states and one-sided nature of the channel. Our work blurs the classical-quantum divide in the context of topology and opens a new path to information resilience in noisy channels, such as terrestrial and satellite-to-ground communication networks.
This paper presents a novel approach to quantum error correction leveraging the topological properties of quantum entanglement. Traditional quantum error correction codes rely on local operations, which are often inefficient and vulnerable to noise. We propose a scheme utilizing multi-body quantum entanglement networks to encode and decode quantum information, capitalizing on the inherent topological protection offered by entanglement. The core mechanism involves the exchange of entangled states to effectively mitigate the impact of noise, achieving robust quantum information transfer without the constraints of localized operations. This work introduces a fundamentally new paradigm for quantum communication, offering a more reliable pathway for transmitting quantum information in the presence of environmental noise. The proposed method aims to overcome the limitations of existing error correction techniques by exploiting the intrinsic robustness of entanglement, paving the way for more practical and scalable quantum communication systems. The key advantage lies in the absence of the need for local quantum gates, which are often a significant bottleneck in quantum communication. We demonstrate, theoretically, the potential for enhanced error correction performance through the strategic manipulation of entangled states.
This paper investigates a novel approach to quantum information encoding and decoding leveraging the principles of topological protection using multi-body quantum entanglement systems. The core concept involves encoding quantum information within topologically protected states, primarily utilizing topological defects such as magnetic vortices, and employing the inherent entanglement properties to provide robust protection against environmental decoherence. We explore the manipulation of these states through external control fields (magnetic and electric) to achieve reliable read and write operations. The theoretical framework presented demonstrates a pathway towards highly resilient quantum information processing, significantly mitigating the challenges posed by decoherence in quantum computing. Specifically, we analyze the robustness of the encoded information against various noise sources, quantifying the protection level achieved through topological features. The proposed method offers a promising route for developing practical quantum computers with enhanced fault tolerance.