French company developing cat-qubit superconducting processors for built-in error protection.
Alice & Bob is a French quantum hardware startup pursuing superconducting 'cat qubits,' which encode information in a way that intrinsically suppresses bit-flip errors and aims to reduce the overhead required for fault tolerance. By targeting hardware-efficient error protection, the company hopes to reach useful logical qubits with fewer physical ones. Its distinctive architecture makes it a notable European contender in the race toward fault-tolerant quantum computing.
Quantum Hardware
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Featured
AWS's managed quantum computing service providing access to multiple hardware providers.
Amazon Braket is AWS's fully managed quantum computing service, giving developers a single environment to run circuits on superconducting, trapped-ion, neutral-atom, and photonic hardware from partners such as IonQ, Rigetti, QuEra, and IQM. It bundles managed simulators, Jupyter notebooks, and the open-source Braket SDK, and integrates with classical AWS compute for hybrid quantum-classical and quantum-machine-learning jobs. It is a default starting point for cloud-based quantum experimentation.
Cloud Platforms
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Neutral-atom quantum computing company that demonstrated a record-scale qubit array.
Atom Computing builds quantum computers from arrays of neutral atoms held in optical traps and drew wide attention by announcing a system exceeding 1,000 qubits, among the largest qubit counts disclosed. The company emphasizes long coherence times and scalable architectures, and has partnered with Microsoft to offer commercial neutral-atom systems through Azure Quantum. Its scaling milestones make it an important name for anyone tracking hardware capable of supporting future quantum AI.
Quantum Hardware
neutral-atom scaling hardware microsoft
Microsoft's cloud quantum platform with the Q# language and multi-provider hardware access.
Azure Quantum is Microsoft's cloud quantum platform offering hardware from IonQ, Quantinuum, Rigetti, and others alongside high-performance simulators. It is paired with the Q# programming language and the Quantum Development Kit, and Microsoft's broader effort includes topological-qubit research and the Azure Quantum Elements platform that fuses HPC, AI, and quantum tools for chemistry and materials. This blend of AI and quantum tooling makes it central to the quantum-AI niche.
Cloud Platforms
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Google's open-source Python framework for building, simulating, and running quantum circuits.
Cirq is Google Quantum AI's open-source Python framework for creating, editing, and invoking noisy intermediate-scale quantum (NISQ) circuits with fine-grained control over qubit layout and gate scheduling. Designed to reflect the constraints of real hardware, it underpins much of Google's experimental work and integrates with TensorFlow Quantum for hybrid quantum-machine-learning models. Cirq is a core tool for researchers targeting near-term quantum devices and quantum-AI prototypes.
SDKs & Frameworks
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Quantum software platform that synthesizes high-level functional models into optimized circuits.
Classiq provides a quantum software development platform built around high-level functional modeling, automatically synthesizing and optimizing the underlying gate-level circuits much like an EDA tool does for classical chips. Developers describe what an algorithm should do, and Classiq's compiler maps it efficiently to a chosen backend such as IBM, IonQ, or Amazon Braket. This abstraction lowers the barrier to building complex quantum and quantum-AI algorithms at scale.
SDKs & Frameworks
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Pioneer of quantum annealing and the Leap real-time quantum cloud service.
D-Wave Quantum is the longest-running commercial quantum computing company and pioneered quantum annealing, an approach well suited to combinatorial optimization problems. Its Advantage systems expose thousands of qubits, and the Leap cloud service offers real-time hybrid solvers alongside the open-source Ocean SDK. D-Wave (NYSE: QBTS) also pursues gate-model development, and its optimization focus makes it a natural fit for AI-adjacent logistics, scheduling, and sampling tasks.
Quantum Hardware
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Featured
Google's quantum hardware and research lab, home to the Sycamore and Willow processors and the Cirq framework.
Google Quantum AI is the Alphabet research division that demonstrated the 2019 'quantum supremacy' experiment on its Sycamore chip and, in 2024, unveiled the Willow processor showing below-threshold quantum error correction. The team develops the open-source Cirq and TensorFlow Quantum frameworks, explicitly bridging quantum circuits and machine learning. Its long-term mission is a large-scale, error-corrected quantum computer, making it a foundational name at the quantum-AI intersection.
Cloud Platforms
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Featured
IBM's superconducting quantum computers and the Qiskit ecosystem, accessible over the cloud.
IBM Quantum operates one of the largest fleets of superconducting quantum processors in the world, including the Heron and Condor families, and exposes them to developers through the cloud-based IBM Quantum Platform. The program publishes a public hardware roadmap targeting error-corrected systems, drives the open-source Qiskit SDK, and supports hybrid workflows that pair quantum circuits with classical AI and machine-learning pipelines. It is a primary reference point for anyone evaluating gate-based quantum computing at scale.
Cloud Platforms
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Featured
Trapped-ion quantum computing company offering systems via major cloud providers and direct access.
IonQ builds trapped-ion quantum computers, a modality prized for long coherence times and high-fidelity all-to-all qubit connectivity. A publicly traded company (NYSE: IONQ), IonQ measures performance using algorithmic qubits and delivers access through Amazon Braket, Microsoft Azure Quantum, and Google Cloud, as well as direct deployments. Its roadmap and quantum-machine-learning research make it a key vendor for organizations exploring quantum AI applications.
Quantum Hardware
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European builder of superconducting quantum computers for HPC centers and cloud access.
IQM Quantum Computers is a Finnish-German company manufacturing superconducting quantum computers and delivering them as on-premises systems to high-performance computing centers and research institutions across Europe, as well as via cloud partners. IQM focuses on full-stack co-design of chips, control electronics, and software, and supplies machines to flagship European supercomputing sites. It is one of the continent's leading hardware vendors integrating quantum acceleration with classical HPC and AI workloads.
Quantum Hardware
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Quantum and quantum-inspired software company focused on finance, AI model compression, and optimization.
Multiverse Computing is a Spanish company applying quantum and quantum-inspired algorithms to finance, energy, and AI. Its Singularity platform tackles optimization and machine-learning problems, while its CompactifAI technology uses tensor-network methods, derived from quantum physics, to compress large language models dramatically without large accuracy loss. This direct fusion of quantum techniques with AI model efficiency places Multiverse firmly within the quantum-AI category this directory tracks.
Quantum AI & ML
quantum-inspired finance ai-compression optimization
NVIDIA's open platform for GPU-accelerated hybrid quantum-classical computing.
CUDA-Q (formerly CUDA Quantum) is NVIDIA's open-source platform for programming hybrid quantum-classical applications, using GPUs to accelerate large-scale circuit simulation and to tightly couple quantum processors with AI supercomputers. It supports a single programming model across simulators and real QPUs from multiple vendors and underpins NVIDIA's quantum-AI strategy of pairing accelerated computing with quantum hardware. For teams blending GPU-driven AI and quantum, CUDA-Q is a central tool.
Quantum AI & ML
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UK superconducting quantum computing company offering systems via cloud and private deployment.
Oxford Quantum Circuits (OQC) is a British superconducting quantum computing company known for its proprietary 'Coaxmon' qubit design, which routes control signals in three dimensions to simplify scaling. OQC offers quantum-computing-as-a-service through cloud platforms and private on-premises installations, including deployments in data centers. As one of the UK's leading commercial hardware builders, it is a relevant option for organizations evaluating European quantum access.
Quantum Hardware
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French neutral-atom quantum computing company focused on analog and digital processors.
Pasqal, co-founded by Nobel laureate Alain Aspect, builds neutral-atom quantum processors in France and is one of Europe's leading quantum hardware companies. It develops the open-source Pulser library for programming analog pulse sequences and pursues quantum machine learning, graph problems, and quantum simulation. Pasqal delivers systems on-premises and through cloud partners, making it a significant European reference point for scalable quantum and quantum-AI workloads.
Quantum Hardware
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Featured
Xanadu's cross-platform library for quantum machine learning and differentiable programming.
PennyLane, built by Xanadu, is the leading open-source library for quantum machine learning, treating quantum circuits as differentiable functions that plug directly into PyTorch, TensorFlow, JAX, and NumPy. It is hardware-agnostic, running on simulators and on IBM, IonQ, Rigetti, and Xanadu devices, and offers extensive tutorials on variational circuits, quantum neural networks, and quantum chemistry. For practitioners exploring the quantum-AI intersection, PennyLane is an essential, well-documented toolkit.
Quantum AI & ML
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Company pursuing large-scale, fault-tolerant photonic quantum computing.
PsiQuantum is building a fault-tolerant, utility-scale photonic quantum computer using silicon-photonics manufacturing techniques compatible with conventional semiconductor fabs. Rather than chasing intermediate NISQ demonstrations, the company targets a machine with roughly a million physical qubits and full error correction, and has announced large-scale facility projects in the United States and Australia. Its manufacturing-first strategy makes it a closely watched contender for practical, large-scale quantum computing.
Quantum Hardware
photonic fault-tolerant semiconductor hardware
Quantum control and error-suppression software company, plus quantum sensing products.
Q-CTRL is an Australian company specializing in quantum control engineering — software that suppresses noise and errors on real quantum hardware to improve algorithm performance. Its Fire Opal product boosts circuit success rates across multiple vendors' machines, while Boulder Opal serves R&D teams and its quantum-sensing line targets navigation without GPS. By focusing on the control layer that makes quantum and quantum-AI algorithms actually run reliably, Q-CTRL fills a distinctive niche.
Control & Software
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IBM's open-source quantum software development kit, the most widely used quantum framework.
Qiskit is the open-source quantum software development kit originated by IBM and arguably the most widely adopted framework for writing, simulating, and running quantum circuits in Python. It spans circuit construction, transpilation, primitives, and runtime execution on IBM hardware, and its ecosystem includes Qiskit Machine Learning and Qiskit Nature for quantum-AI and chemistry applications. A large community, extensive documentation, and textbook resources make it a default learning path into quantum computing.
SDKs & Frameworks
sdk open-source python ibm
French photonic quantum computing company offering cloud access and the Perceval framework.
Quandela is a French photonic quantum computing company that builds single-photon sources and photonic processors, offering access to its machines through a cloud service and on-premises deployments. It develops the open-source Perceval framework for programming linear-optical quantum circuits and explores photonic approaches to quantum machine learning. As a vertically integrated European photonics player, Quandela is a meaningful option for teams studying light-based quantum computing and its AI applications.
Quantum Hardware
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Featured
Integrated quantum computing company formed from Honeywell Quantum Solutions and Cambridge Quantum.
Quantinuum was formed by combining Honeywell Quantum Solutions with Cambridge Quantum and operates the H-Series trapped-ion computers, which hold record quantum volume figures. Beyond hardware it ships the TKET compiler, the InQuanto chemistry platform, and Quantum Natural Language Processing research that directly targets quantum AI. The company also publishes verifiable quantum-random-number work, positioning it across the full quantum software-and-hardware stack.
Quantum Hardware
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Developer of diamond-based, room-temperature quantum accelerators for edge and HPC.
Quantum Brilliance, an Australian-German company, develops quantum computing hardware based on nitrogen-vacancy centers in synthetic diamond, which can operate at room temperature without the bulky cryogenics most architectures require. This enables compact 'quantum accelerators' intended to sit alongside classical processors in data centers, HPC clusters, and eventually edge devices. Its distinctive form factor makes it a notable contender for embedding quantum capability close to AI and HPC workloads.
Quantum Hardware
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Maker of the OPX quantum control platform that orchestrates qubits across hardware types.
Quantum Machines builds the OPX line of quantum control systems and the QUA programming language, providing the classical electronics and software that orchestrate qubits in real time across superconducting, trapped-ion, and other modalities. Its platform supports the fast feedback and complex pulse sequences that error correction and advanced algorithms demand. By powering the control layer for many labs and vendors, Quantum Machines is critical infrastructure beneath quantum and quantum-AI experiments.
Control & Software
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Neutral-atom quantum computing company offering the 256-qubit Aquila system via Amazon Braket.
QuEra Computing develops neutral-atom quantum computers based on research from Harvard and MIT, using arrays of individually trapped atoms manipulated by optical tweezers and Rydberg interactions. Its 256-qubit Aquila machine is available on Amazon Braket, supporting both analog and emerging digital modes. Neutral-atom systems scale qubit counts rapidly and support flexible geometries, making QuEra a leading option for quantum optimization and quantum-simulation research.
Quantum Hardware
neutral-atom analog braket hardware
Open-source Python framework for simulating the dynamics of open quantum systems.
QuTiP, the Quantum Toolbox in Python, is a widely used open-source framework for simulating the dynamics of open quantum systems, including decoherence, master equations, and time-dependent Hamiltonians. Heavily used in academic research and quantum hardware development, it provides the numerical backbone for modeling qubits, control pulses, and noise. Although not tied to a single vendor, QuTiP is an indispensable simulation tool underpinning much quantum and quantum-AI algorithm research.
SDKs & Frameworks
simulation open-source python research
Full-stack superconducting quantum computing company with cloud access through Quantum Cloud Services.
Rigetti Computing designs and manufactures its own superconducting quantum processors in an in-house fabrication facility and delivers them through Quantum Cloud Services and partner clouds such as Amazon Braket and Azure Quantum. The publicly listed firm (NASDAQ: RGTI) develops modular, multi-chip Ankaa-class systems and the pyQuil software framework. Its full-stack control of hardware and software makes it relevant to teams benchmarking gate-based quantum and hybrid quantum-classical workloads.
Quantum Hardware
superconducting full-stack public-company qcs
Featured
Alphabet spinout combining AI and quantum techniques for security, simulation, and life sciences.
SandboxAQ, a company that spun out of Alphabet, brands its work as 'AQ' — the combination of AI and quantum techniques. It applies large quantitative models and quantum-inspired simulation to drug discovery, materials, and navigation, and is a major provider of post-quantum cryptography and cryptographic-inventory tools for enterprises preparing for quantum threats. As an explicit AI-plus-quantum venture, SandboxAQ is a flagship example of the quantum-AI thesis.
Quantum AI & ML
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Xanadu's open-source framework for designing and simulating photonic quantum circuits.
Strawberry Fields is Xanadu's open-source Python framework for designing, simulating, and executing photonic quantum circuits using continuous-variable quantum computing. It includes a simulator suite and connects to Xanadu's cloud photonic hardware, and it has been used for Gaussian boson sampling and photonic quantum machine learning research. As a specialized counterpart to gate-model toolkits, Strawberry Fields is a key resource for researchers exploring the photonic and quantum-AI corners of the field.
SDKs & Frameworks
photonic open-source simulation xanadu
Google's library for building hybrid quantum-classical machine-learning models.
TensorFlow Quantum (TFQ) is Google's open-source library for hybrid quantum-classical machine learning, letting researchers embed parameterized quantum circuits built in Cirq directly inside TensorFlow models. It supports quantum data, quantum neural networks, and variational algorithms, and provides differentiation through quantum layers so they train like any other Keras component. TFQ is a foundational tool for experimenting with quantum-enhanced machine learning and is a defining project of the quantum-AI field.
Quantum AI & ML
quantum-ml open-source tensorflow google
Swiss quantum-as-a-service company spanning algorithms, security, and quantum-inspired computing.
Terra Quantum is a Swiss company offering quantum-as-a-service across algorithms, optimization, and security. Its work includes hybrid quantum-classical neural networks and quantum-inspired tensor-network methods that run on classical hardware today, alongside post-quantum cryptography and a quantum key distribution offering. By packaging quantum and quantum-inspired machine learning into deployable enterprise services, Terra Quantum is an applied example of the quantum-AI convergence at the center of this directory.
Quantum AI & ML
quantum-as-a-service quantum-ml security europe
Featured
Photonic quantum computing company and creator of the PennyLane quantum machine-learning library.
Xanadu builds photonic quantum computers and is one of the most influential names in quantum machine learning through PennyLane, its open-source library for differentiable quantum programming and quantum neural networks. The company offers cloud access to its Borealis and X-Series photonic devices and develops the Strawberry Fields framework. By making automatic differentiation native to quantum circuits, Xanadu sits squarely at the quantum-AI intersection this directory covers.
Quantum AI & ML
photonic pennylane quantum-ml cloud
Industrial generative AI company with roots in quantum and quantum-inspired algorithms.
Zapata AI grew out of quantum computing research at Harvard and pioneered enterprise quantum software through its Orquestra platform before pivoting toward industrial generative AI. The company develops quantum-inspired techniques, such as tensor networks and generative models, to tackle optimization and forecasting problems on classical hardware while remaining quantum-ready. Its trajectory from pure quantum to AI built on quantum methods illustrates the practical path many quantum-AI ventures are taking.
Quantum AI & ML
generative-ai quantum-inspired enterprise orquestra
QAI = Quantum AI: where quantum computing meets artificial intelligence.
The two most consequential computing frontiers of this decade are quantum computing and artificial intelligence, and they are increasingly converging. QAIDirectory exists to map that convergence. The "QAI" in our name stands for Quantum AI — the rapidly growing field where quantum processors, quantum algorithms, and quantum-inspired mathematics meet machine learning, optimization, and the broader AI stack. Rather than chasing headlines, we index real, verifiable organizations and tools and link each one directly to its official website, so you can go straight to the source.
Quantum computing is not one technology but several competing physical approaches, and this directory deliberately reflects that diversity. Superconducting qubits power machines from IBM Quantum, Google Quantum AI, Rigetti, IQM, and Oxford Quantum Circuits. Trapped-ion systems from IonQ and Quantinuum trade raw qubit count for high fidelity and all-to-all connectivity. Neutral-atom builders such as QuEra, Pasqal, and Atom Computing scale qubits using optical tweezers and Rydberg interactions, while photonic companies like Xanadu, PsiQuantum, and Quandela compute with light. D-Wave pioneered a different path entirely with quantum annealing for optimization, and Quantum Brilliance pursues room-temperature diamond accelerators. Each modality carries different trade-offs in coherence, error rates, and the road to fault tolerance.
Why quantum and AI belong in one directory
The link between quantum and AI is not marketing — it is mathematical and architectural. Quantum machine learning treats quantum circuits as differentiable, trainable models: libraries such as PennyLane (Xanadu) and TensorFlow Quantum (Google) plug parameterized quantum circuits directly into PyTorch, JAX, and TensorFlow so they train like any other neural layer. At the same time, quantum-inspired methods borrowed from physics are reshaping classical AI: Multiverse Computing's tensor-network techniques compress large language models, and companies like Terra Quantum and Zapata AI ship hybrid quantum-classical and quantum-inspired models that run on today's hardware. SandboxAQ, an Alphabet spinout, brands its entire mission as "AQ" — AI plus quantum — applying large quantitative models and quantum simulation to drug discovery, materials, and security.
What you will find here
We organize listings into five practical categories. Quantum Hardware covers the physical processors across every qubit modality. Cloud Platforms — Amazon Braket, Microsoft Azure Quantum, IBM Quantum — let you run circuits on real machines without owning a dilution refrigerator. SDKs & Frameworks such as Qiskit, Cirq, QuTiP, Strawberry Fields, and Classiq are the software you actually write algorithms in. Quantum AI & ML gathers the tools and companies at the explicit intersection of the two fields, including NVIDIA's GPU-accelerated CUDA-Q. And Control & Software captures the often-overlooked layer — Q-CTRL's error suppression, Quantum Machines' control systems — that makes any of it run reliably.
Every entry in QAIDirectory is chosen for relevance and described in our own words, with an editorial summary and a link to a real, official URL. We never invent company names, funding figures, or capabilities, and we flag publicly traded firms and notable milestones only where they are verifiable. Whether you are an engineer choosing a framework, a researcher comparing hardware, an investor mapping the sector, or simply curious about who is building the quantum-AI future, this directory is a clean, fast, and honest starting point.