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Y. Chai, D. Ghoshal, N. P. Tiwari, . Kolar, B. Pingault, H. Bernien, T. Zhong A hybrid quantum network linking telecom-wavelength atomic and solid-state nodes,
(2026-03-06),
arXiv:2602.02653 arXiv:2602.02653
Photonic links between disparate quantum technologies such as photon sources, memories, processors, clocks, and sensors are key to scaling quantum networks and realizing a versatile quantum internet for secure quantum communication, distributed quantum computing, and entanglement-enhanced metrology. In practice, each technology is most suitably implemented on a different quantum platform; the substantial spectral mismatch between them, along with scarce native telecom interfaces, thus poses a major bottleneck to achieving efficient interconnections over long distances. Here we demonstrate the first deployed two-node hybrid network that operates entirely in the telecom C-band. Our approach uses no quantum frequency conversion or external filtering; instead, we develop a neutral atom single photon source and a solid-state rare-earth quantum memory that both operate in previously unexplored telecom regimes with state-of-the-art performance. The source achieves a high single-photon purity at 46 kcps, and the memory a storage efficiency of 10.6\\% with high multimode capacity. We leverage the intrinsic tunability of both systems to optimize their spectral overlap and demonstrate microsecond-level storage and retrieval with a large time-bandwidth product. Moreover, we showcase real-world networking competencies such as support for multiplexing across 37 temporal modes and preservation of non-classicality over fibers of 10.6 km (metropolitan) and 49.2 km (laboratory). Our work establishes a backbone for telecom-native quantum repeater links and unlocks a path towards high-bandwidth, large-scale quantum networking.
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F. Cesa, A. Di Fini, D. A. Korbany, R. Tricarico, H. Bernien, H. Pichler, L. Piroli Engineering discrete local dynamics in globally driven dual-species atom arrays,
(2026-01-23),
arXiv:2601.16961 arXiv:2601.16961
We introduce a method for engineering discrete local dynamics in globally-driven dual-species neutral atom experiments, allowing us to study emergent digital models through uniform analog controls. Leveraging the new opportunities offered by dual-species systems, such as species-alternated driving, our construction exploits simple Floquet protocols on static atom arrangements, and benefits of generalized blockade regimes (different inter- and intra-species interactions). We focus on discrete dynamical models that are special examples of Quantum Cellular Automata (QCA), and explicitly consider a number of relevant examples, including the kicked-Ising model, the Floquet Kitaev honeycomb model, and the digitization of generic translation-invariant nearest-neighbor Hamiltonians (e.g., for Trotterized evolution). As an application, we study chaotic features of discretized many-body dynamics that can be detected by leveraging only demonstrated capabilities of globally-driven experiments, and benchmark their ability to discriminate chaotic evolution.
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R. P. White, V. Ramesh, A. Impertro, S. Anand, F. Cesa, G. Giudici, T. Iadecola, H. Pichler, H. Bernien Quantum Cellular Automata on a Dual-Species Rydberg Processor,
(2026-01-22),
arXiv:2601.16257 arXiv:2601.16257
As quantum devices scale to larger and larger sizes, a significant challenge emerges in scaling their coherent controls accordingly. Quantum cellular automata (QCAs) constitute a promising framework that bypasses this control problem: universal dynamics can be achieved using only a static qubit array and global control operations. Despite an extensive history of theoretical explorations and proposals, QCAs have not been experimentally explored in the context of highly-scalable globally-controlled systems. Here we realize QCAs on a dual-species Rydberg array of rubidium and cesium atoms, leveraging independent global control of each species to perform multiple quantum protocols. Seeding an automaton with different initial states, we explore many-body dynamics of quasiparticles and grow GHZ states across both species, highlighting the flexibility of our approach. We further develop a second automaton using a novel mediated entangling gate, enabling generation of 96.7(1.7)\%-fidelity Bell states, 17-qubit cluster states, and high-connectivity graph states. Our results demonstrate that simple global controls enable access to a rich variety of applications through the QCA framework. The versatility and scalability of QCAs present compelling opportunities for the development of quantum information systems, as well as new perspectives on quantum many-body dynamics.
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R. White, V. Ramesh, A. Impertro, S. Anand, F. Cesa, G. Giudici, T. Iadecola, H. Pichler, H. Bernien Quantum Cellular Automata on a Dual-Species Rydberg Processor,
(2026-01-22),
arXiv:2601.16257 arXiv:2601.16257
As quantum devices scale to larger and larger sizes, a significant challenge emerges in scaling their coherent controls accordingly. Quantum cellular automata (QCAs) constitute a promising framework that bypasses this control problem: universal dynamics can be achieved using only a static qubit array and global control operations. We realize QCAs on a dual-species Rydberg array of rubidium and cesium atoms, leveraging independent global control of each species to perform a myriad of quantum protocols. With simple pulse sequences, we explore many-body dynamics and generate a variety of entangled states, including GHZ states, 96.7(1.7)\\%-fidelity Bell states, 17-qubit cluster states, and high-connectivity graph states. The versatility and scalability of QCAs offers compelling routes for scaling quantum information systems with global controls, as well as new perspectives on quantum many-body dynamics.
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D. Awschalom, H. Bernien, R. Hanson, W. D. Oliver, J. Vuckovic Challenges and opportunities for quantum information hardware,
Science 390 1004-1010 (2025-12-04),
http://dx.doi.org/10.1126/science.adz8659 doi:10.1126/science.adz8659
Quantum technologies have made impressive progress over the past decade. In some areas, such as quantum sensing and key distribution, these technologies are moving from the laboratory to enable real-world applications. However, for areas such as quantum computing, entanglement-enhanced sensing, and a global quantum internet, we are in an equivalent of the early transistor age, and hardware breakthroughs are required in multiple arenas to reach the performance necessary for the envisioned applications. In this Review, we assess the current state of the art of quantum information hardware and identify key challenges and opportunities ahead. We draw inspiration from the history of scaling and development of classical electronics and photonics to anticipate progress in the field.
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F. Gu, S. G. Menon, D. Maier, A. Das, T. Chakraborty, W. Tittel, H. Bernien Hybrid Quantum Repeaters with Ensemble-based Quantum Memories and Single-spin Photon Transducers,
npj Quantum Information 11 182 (2025-11-20),
http://dx.doi.org/10.1038/s41534-025-01119-5 doi:10.1038/s41534-025-01119-5
Reliable quantum communication over hundreds of kilometers is a daunting yet necessary requirement for a quantum internet. To overcome photon loss, the deployment of quantum repeater stations between distant network nodes is necessary. A plethora of different quantum hardware is being developed for this purpose, each platform with its own opportunities and challenges. Here, we propose to combine two promising hardware platforms in a hybrid quantum repeater architecture to lower the cost and boost the performance of long-distance quantum communication. We outline how ensemble-based quantum memories combined with single-spin photon transducers, which can transfer quantum information between a photon and a single spin, can facilitate massive multiplexing, efficient photon generation, and quantum logic for amplifying communication rates. As a specific example, we describe how a single Rubidium (Rb) atom coupled to nanophotonic resonators can function as a high-rate, telecom-visible entangled photon source with the visible photon being compatible with storage in a Thulium-doped crystal memory (Tm-memory) and the telecom photon being compatible with low loss fiber propagation. We experimentally verify that Tm and Rb transitions are in resonance with each other. Our analysis shows that by employing up to 9 repeater stations, each equipped with two Tm-memories capable of holding up to 625 storage modes, along with four single Rb atoms, one can reach a quantum communication rate of about 10 secret bits per second across distances of up to 1000 km.
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B. Li, D. Dilley, A. Gonzales, T. A. Hahn, R. White, R. Arnon-Friedman, H. Bernien, Z. Saleem, L. Jiang Efficient Entanglement Purification Circuit Design for Dual-Species Atom Arrays,
(2025-09-15),
arXiv:2509.12370 arXiv:2509.12370
Entanglement purification protocols (EPPs) are essential for generating high-fidelity entangled states in noisy quantum systems, enabling robust quantum networking and computation. Building on the circuit of the foundational recurrence protocol, we generalize two-way EPPs to arbitrary stabilizer codes. Through analytical derivations and noisy circuit simulations incorporating circuit-level noise, we demonstrate enhanced purification performance, with fidelity improvements and finite distillation rates for distillable input states. We propose efficient circuit designs for EPPs tailored to dual-species Rydberg atom arrays, leveraging species-specific laser control and interspecies Rydberg interactions. Introducing a low-overhead operation set, the dual-species atom convenient operation set, we facilitate straightforward compilation of EPP circuits without the need for ancillary atoms or complex atom rearrangements. Our framework provides practical guidance for near-term implementations on dual-species platforms, advancing towards scalable entanglement distribution in neutral atom systems and paving the way for fault-tolerant quantum technologies.
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N. K. Harle, B. Chen, B. Bao, H. Bernien atommovr: An open-source simulation framework for rearrangement in atomic arrays,
(2025-08-04),
arXiv:2508.02670 arXiv:2508.02670
The task of atom rearrangement has emerged in the last decade as a fundamental building block for the development of neutral atom-based quantum processors. However, despite many recent efforts to develop algorithms with favorable asymptotic scaling, no time-optimal algorithm has been developed for any rearrangement task. Moreover, no open-source code exists to reproduce or benchmark existing algorithms, and to assist the development of new rearrangement protocols. To address this deficiency, we develop an open-source simulation framework for developing, comparing, and benchmarking algorithms under realistic and customizable noise models. Using this framework, we \textbf{a)} numerically extract lower bounds for the scaling of a time-optimal rearrangement algorithm and compare it to existing heuristic algorithms \textbf{b)} develop a naive dual-species algorithm able to prepare arbitrary targets with near-unity success rate. With this framework, we hope to develop a common tool for the community to study rearrangement, lower the barrier to entry for new experimental groups, and stimulate progress in developing algorithms which approach time-optimal scaling.
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F. Cesa, H. Bernien, H. Pichler Fast and Error-Correctable Quantum RAM,
(2025-03-24),
arXiv:2503.19172v1 arXiv:2503.19172v1
Quantum devices can process data in a fundamentally different way than classical computers. To leverage this potential, many algorithms require the aid of a quantum Random Access Memory (QRAM), i.e. a module capable of efficiently loading datasets (both classical and quantum) onto the quantum processor. However, a realization of this fundamental building block is still outstanding, since existing proposals require prohibitively many resources for reliable implementations, or are not compatible with current architectures. Moreover, present approaches cannot be scaled-up, as they do not allow for efficient quantum error-correction. Here we develop a QRAM design, that enables fast and robust QRAM calls, naturally allows for fault-tolerant and error-corrected operation, and can be integrated on present hardware. Our proposal employs a special quantum resource state that is consumed during the QRAM call: we discuss how it can be assembled and processed efficiently in a dedicated module, and give detailed blueprints for modern neutral-atom processors. Our work places a long missing, fundamental component of quantum computers within reach of currently available technology; this opens the door to algorithms featuring practical quantum advantage, including search or oracular problems, quantum chemistry and machine learning.
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T. A. Hahn, R. P. White, H. Bernien, R. Arnon-Friedman Deterministic high-rate entanglement distillation with neutral atom arrays,
(2025-03-01),
arXiv:2503.00445 arXiv:2503.00445
The goal of an entanglement distillation protocol is to convert large quantities of noisy entangled states into a smaller number of high-fidelity Bell pairs. The celebrated one-way hashing method is one such protocol, and it is known for being able to efficiently and deterministically distill entanglement in the asymptotic limit, i.e., when the size of the quantum system is very large. In this work, we consider setups with finite resources, e.g., a small fixed number of atoms in an atom array, and derive lower bounds on the distillation rate for the one-way hashing method. We provide analytical as well as numerical bounds on its entanglement distillation rate -- both significantly tighter than previously known bounds. We then show how the one-way hashing method can be efficiently implemented with neutral atom arrays. The combination of our theoretical results and the experimental blueprint we provide indicate that a full coherent implementation of the one-way hashing method is within reach with state-of-the-art quantum technology.
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S. G. Menon, N. Glachman, M. Pompili, A. Dibos, H. Bernien An integrated atom array-nanophotonic chip platform with background-free imaging,
Nat. Commun. 15 6156 (2024-07-22),
http://dx.doi.org/10.1038/s41467-024-50355-4 doi:10.1038/s41467-024-50355-4
Arrays of neutral atoms trapped in optical tweezers have emerged as a leading platform for quantum information processing and quantum simulation due to their scalability, reconfigurable connectivity, and high-fidelity operations. Individual atoms are promising candidates for quantum networking due to their capability to emit indistinguishable photons that are entangled with their internal atomic states. Integrating atom arrays with photonic interfaces would enable distributed architectures in which nodes hosting many processing qubits could be efficiently linked together via the distribution of remote entanglement. However, many atom array techniques cease to work in close proximity to photonic interfaces, with atom detection via standard fluorescence imaging presenting a major challenge due to scattering from nearby photonic devices. Here, we demonstrate an architecture that combines atom arrays with up to 64 optical tweezers and a millimeter-scale photonic chip hosting more than 100 nanophotonic cavities. We achieve high-fidelity ( ~ 99.2%), background-free imaging in close proximity to nanofabricated cavities using a multichromatic excitation and detection scheme. The atoms can be imaged while trapped a few hundred nanometers above the dielectric surface, which we verify using Stark shift measurements of the modified trapping potential. Finally, we rearrange atoms into defect-free arrays and load them simultaneously onto the same or multiple devices.
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R. J. Valencia-Tortora, N. Pancotti, M. Fleischhauer, H. Bernien, J. Marino Rydberg Platform for Nonergodic Chiral Quantum Dynamics,
Phys. Rev. Lett. 132 223201 (2024-05-29),
http://dx.doi.org/10.1103/PhysRevLett.132.223201 doi:10.1103/PhysRevLett.132.223201
We propose a mechanism for engineering chiral interactions in Rydberg atoms via a directional antiblockade condition, where an atom can change its state only if an atom to its right (or left) is excited. The scalability of our scheme enables us to explore the many-body dynamics of kinetically constrained models with unidirectional character. We observe nonergodic behavior via either scars, confinement, or localization, upon simply tuning the strength of two driving fields acting on the atoms. We discuss how our mechanism persists in the presence of classical noise and how the degree of chirality in the interactions can be tuned, opening towards the frontier of directional, strongly correlated, quantum mechanics using neutral atoms arrays.
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A. Bilgin, I. N. Hammock, J. Estes, Y. Jin, H. Bernien, A. A. High, G. Galli Donor-acceptor pairs in wide-bandgap semiconductors for quantum technology applications,
npj Comput Mater 10 7 (2024-01-06),
http://dx.doi.org/10.1038/s41524-023-01190-6 doi:10.1038/s41524-023-01190-6
We propose a quantum science platform utilizing the dipole-dipole coupling between donor-acceptor pairs (DAPs) in wide bandgap semiconductors to realize optically controllable, long-range interactions between defects in the solid state. We carry out calculations based on density functional theory (DFT) to investigate the electronic structure and interactions of DAPs formed by various substitutional point-defects in diamond and silicon carbide (SiC). We determine the most stable charge states and evaluate zero phonon lines using constrained DFT and compare our results with those of simple donor-acceptor pair (DAP) models. We show that polarization differences between ground and excited states lead to unusually large electric dipole moments for several DAPs in diamond and SiC. We predict photoluminescence spectra for selected substitutional atoms and show that while B-N pairs in diamond are challenging to control due to their large electron-phonon coupling, DAPs in SiC, especially Al-N pairs, are suitable candidates to realize long-range optically controllable interactions.
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S. Anand, C. E. Bradley, R. P. White, V. Ramesh, K. Singh, H. Bernien A dual-species Rydberg array,
Nature Phys. 20 1744 (2024-01-01),
http://dx.doi.org/10.1038/s41567-024-02638-2 doi:10.1038/s41567-024-02638-2
Large-scale Rydberg atom arrays are used for highly coherent analogue quantum simulations and for digital quantum computations. However, advanced quantum protocols, such as quantum error correction, require midcircuit qubit operations, including the replenishment, reset and read-out of a subset of qubits. A compelling strategy for unlocking these capabilities is a dual-species architecture in which a second atomic species is controlled independently and entangled with the first through Rydberg interactions. Here, we realize a dual-species Rydberg array consisting of rubidium and caesium atoms and explore regimes of interactions and dynamics not accessible in single-species architectures. We achieve enhanced interspecies interactions by electrically tuning the Rydberg states close to a Förster resonance. In this regime, we demonstrate an interspecies Rydberg blockade and implement a quantum state transfer from one species to another. We then generate a Bell state between Rb and Cs hyperfine qubits through an interspecies controlled-phase gate. Finally, we combine interspecies entanglement with a native midcircuit read-out to achieve quantum non-demolition measurements.