The H1-1 system set new benchmarks for quantum volume and demonstrated the power of high-fidelity, all-to-all connected trapped-ion qubits.
The Quantinuum H1-1 represents a significant milestone in the development of commercial quantum computing, particularly within the trapped-ion technology paradigm. While now superseded by more advanced systems like the H2, the H1-1 served as a foundational platform, pushing the boundaries of what was achievable in terms of qubit count, connectivity, and fidelity. Launched commercially in 2021, following its announcement in 2020, it quickly established itself as a leading system for researchers and developers seeking to explore the potential of quantum algorithms on real hardware.
As a data analyst evaluating quantum hardware, the H1-1 offers a rich case study in the evolution of quantum processors. Its architecture, based on trapped-ion qubits, leverages individual atomic ions held in place by electromagnetic fields, with their internal hyperfine states encoding quantum information. This approach inherently provides several advantages, most notably high qubit coherence times and the potential for very high gate fidelities. The H1-1, specifically, was engineered to capitalize on these strengths, delivering a system that, for its time, offered unparalleled performance in certain key metrics.
One of the H1-1's most celebrated achievements was its record-breaking Quantum Volume (QV) score. In 2023, it achieved a QV of 1,048,576, a testament to its combined strengths in qubit count, connectivity, gate fidelity, and low error rates. Quantum Volume is a hardware-agnostic metric designed to quantify the overall computational capability of a quantum computer, taking into account not just the number of qubits but also their quality and connectivity. This high QV score indicated the H1-1's ability to execute complex quantum circuits with a significant number of qubits and gate operations before errors accumulated to render the computation meaningless. For data analysts, such benchmarks are crucial for understanding the practical utility of a quantum processor for real-world problems, moving beyond mere qubit counts to a more holistic assessment of performance.
The H1-1's design also showcased the innovative Quantum Charge-Coupled Device (QCCD) architecture, which allows for the dynamic rearrangement and interaction of ions. This capability is central to achieving the system's all-to-all connectivity, a feature that dramatically simplifies circuit compilation and reduces the need for costly SWAP gates, which are often required in systems with more restrictive connectivity patterns. This architectural choice has profound implications for the types of algorithms that can be efficiently executed and the overall depth of circuits that can be reliably run. Understanding these architectural nuances is vital for any data analyst attempting to map computational problems onto quantum hardware effectively.
Despite its status as a superseded system, the H1-1's legacy continues to influence quantum hardware development. Its performance metrics, particularly its fidelities and QV scores, set a high bar for subsequent generations of quantum computers. For those studying the historical progression of quantum computing, or seeking to understand the practical implications of different hardware architectures, the H1-1 remains an invaluable reference point. Its commercial availability through major cloud platforms also made it accessible to a broad user base, fostering early exploration and development of quantum applications.
| Spec | Details |
|---|---|
| System ID | QH11 |
| Vendor | Quantinuum |
| Technology | Trapped-ion |
| Status | Superseded commercial QPU |
| Primary metric | Physical qubits |
| Metric meaning | Number of fully connected trapped-ion qubits |
| Qubit mode | Ions trapped in electromagnetic fields, using hyperfine states as qubits |
| Connectivity | Linear chain all-to-all via ion transport |
| Native gates | Single-qubit rotations | ZZ | Arbitrary angle ZZ | SU(4) |
| Error rates & fidelities | 1Q infidelity 2e-5 typical (2025) | 2Q 1e-3 | SPAM 2e-3 | Memory 2e-4 |
| Benchmarks | QV 1,048,576 (2023) | RQVM 1000 | Circuit depth benchmarks |
| How to access | Subscription via Quantinuum or clouds |
| Platforms | Azure Quantum | AWS Braket | Direct API |
| SDKs | Qiskit | Cirq | TKET |
| Regions | US | EU |
| Account requirements | Subscription account |
| Pricing model | Subscription |
| Example prices | HQC formula 5 + C*(N1q +10N2q +5Nm)/5000 | Azure 135k/mo for 10k HQC |
| Free tier / credits | Research credits via QCUP |
| First announced | 2020 |
| First available | 2021 |
| Major revisions | Upgraded to 20 qubits (2022) | Arbitrary gates (2022) |
| Retired / roadmap | Superseded by H2 2023; H1 retired roadmap |
| Notes | H1-1 and H1-2 are separate machines; H1-1 has higher QV records |
The Quantinuum H1-1 system, while now superseded, offered a compelling profile for quantum computation, particularly for applications requiring high fidelity and flexible connectivity. From a data analyst's perspective, understanding its core capabilities and limitations is crucial for appreciating its historical impact and for drawing comparisons with contemporary and future quantum processors.
The H1-1 is built upon trapped-ion technology, specifically utilizing individual atomic ions held in a linear chain by electromagnetic fields. The qubits themselves are encoded in the hyperfine states of these ions. This choice of technology is known for providing excellent qubit coherence times and the potential for very high gate fidelities, which are critical for executing deep quantum circuits. The system featured 20 physical qubits as of its 2022 upgrade, a significant number for its time, especially considering the quality of these qubits. The 'physical qubit' metric here refers to fully functional, addressable qubits available for computation.
One of the H1-1's standout features is its all-to-all connectivity, achieved through a unique ion transport mechanism within its linear chain architecture. Unlike many other quantum computing platforms where qubits only interact with their nearest neighbors, the H1-1 could bring any two qubits into interaction, effectively creating a fully connected graph. This capability is a major advantage for quantum algorithm developers, as it eliminates the need for costly and error-prone SWAP gates to move quantum information between non-adjacent qubits. This directly translates to simpler circuit compilation, reduced circuit depth, and ultimately, higher fidelity execution of complex algorithms. For a data analyst, this means that algorithms with high connectivity requirements, such as certain quantum chemistry simulations or optimization problems, could be mapped onto the H1-1 with greater efficiency and less overhead.
The H1-1 supports a powerful and flexible native gate set, including single-qubit rotations, ZZ gates, arbitrary angle ZZ gates, and SU(4) gates. Single-qubit rotations are fundamental for manipulating individual qubit states. The ZZ gate, a two-qubit entangling gate, is a common primitive in many quantum algorithms. The inclusion of arbitrary angle ZZ gates provides significant flexibility, allowing for fine-tuned control over entanglement strength and duration, which can be beneficial for variational algorithms or specific quantum simulations. The SU(4) gate is a universal two-qubit gate that can implement any two-qubit unitary operation, offering a high degree of expressiveness and potentially reducing the total number of gates required for certain operations. This rich gate set empowers developers to construct a wide range of quantum circuits efficiently.
The H1-1 was notable for its high gate fidelities, a hallmark of trapped-ion systems. As of 2025 projections (based on vendor documentation), typical single-qubit (1Q) infidelity was 2e-5. For two-qubit (2Q) gates, the infidelity was 1e-3. State Preparation and Measurement (SPAM) errors were around 2e-3, and qubit memory errors were approximately 2e-4. These figures represent some of the lowest error rates available on commercial quantum hardware during its operational period. High fidelities are paramount for executing deep quantum circuits, as errors accumulate multiplicatively with each gate operation. For data analysts, these low error rates imply that more complex and longer-running algorithms could be attempted on the H1-1 with a higher probability of obtaining meaningful results, compared to systems with higher error floors.
The H1-1 consistently demonstrated strong performance in industry-standard benchmarks. Its most prominent achievement was a Quantum Volume (QV) of 1,048,576 in 2023. Quantum Volume is a comprehensive metric that assesses a quantum computer's effective computational power by considering qubit count, connectivity, gate fidelity, and error rates. This high QV score indicated the H1-1's ability to run deep, complex circuits on a significant number of qubits. Additionally, it achieved an RQVM (Randomized Quantum Volume Measurement) of 1000, another indicator of its robust performance. The system also excelled in various circuit depth benchmarks, demonstrating its capacity to execute circuits with thousands of gates before fidelity limitations became prohibitive. These benchmarks provide concrete, comparable data points for evaluating the H1-1's practical utility.
While excelling in fidelity and connectivity, trapped-ion systems like the H1-1 typically exhibit lower gate speeds compared to superconducting qubit systems. This means that while individual operations are highly accurate, the overall execution time for a circuit might be longer. However, this trade-off is often acceptable given the benefits of high fidelity and long coherence times, which allow for deeper circuits and more reliable results. The H1-1's architecture, based on the scalable QCCD (Quantum Charge-Coupled Device) model, also highlighted a path towards future scalability, addressing a common challenge in quantum hardware development. For a data analyst, choosing between different quantum technologies often involves weighing these trade-offs based on the specific requirements of the problem at hand – whether high speed or high fidelity is the more critical factor.
| System | Status | Primary metric |
|---|---|---|
| Quantinuum H3 | Commercial QPU | Physical qubits: 98 (2025) |
| Quantinuum H2-1 | Commercial QPU | Physical qubits: 56 (2024) |
| Quantinuum H1-2 | Superseded commercial QPU | Physical qubits: 20 (2022) |
The Quantinuum H1-1 system represents a pivotal chapter in the commercialization of trapped-ion quantum computing, marked by a rapid evolution from its initial announcement to its eventual supersession. Understanding its timeline provides crucial context for its impact and the pace of innovation in the quantum hardware landscape.
The H1-1's journey from announcement to supersession highlights a period of intense development and commercialization in quantum computing. Its contributions, particularly in demonstrating high-fidelity operations and achieving record Quantum Volume, have left an indelible mark on the field, paving the way for the more powerful quantum computers available today.
Verification confidence: High. Specs can vary by revision and access tier. Always cite the exact device name + date-stamped metrics.
The H1-1's primary advantage stemmed from its trapped-ion technology, which inherently offers high qubit coherence times and excellent gate fidelities. Coupled with its all-to-all connectivity via ion transport, it allowed for the execution of deeper and more complex quantum circuits with fewer errors compared to many contemporary systems.
The H1-1 system was upgraded to feature 20 physical qubits in 2022. In this context, 'physical qubits' refers to the actual, individual trapped-ion qubits that were fully functional and available for quantum computation, as opposed to logical qubits or qubits that might be present but not fully addressable or usable.
The H1-1 achieved a record-breaking Quantum Volume (QV) of 1,048,576 in 2023. This was highly significant because QV is a comprehensive, hardware-agnostic metric that assesses a quantum computer's overall computational capability, considering not just qubit count but also connectivity, gate fidelity, and error rates. A high QV indicates the system's ability to execute complex, deep circuits reliably.
No, the Quantinuum H1-1 is considered a superseded commercial QPU. Its roadmap was retired in 2023 as it was succeeded by the next generation of Quantinuum's H-series systems (e.g., H2). While it was publicly accessible via subscription and cloud platforms during its operational lifetime, it is no longer the primary system offered for new commercial or research use.
The H1-1 operated on a subscription-based pricing model. Costs were typically calculated using an HQC (H-System Quantum Credit) formula, which factored in the number of single-qubit gates, two-qubit gates, and measurements. For example, an Azure offering was priced at 135k/month for 10,000 HQC. Direct subscriptions often had a minimum monthly commitment, usually around 125k/month.
The primary trade-off for the H1-1, typical of trapped-ion systems, was generally lower gate speed compared to superconducting qubit systems. However, this was balanced by its significant advantages in high fidelity and long coherence times, which allowed for the execution of much deeper and more reliable quantum circuits. Its all-to-all connectivity also simplified circuit compilation, offsetting some of the speed differences.
Given its high fidelity, all-to-all connectivity, and robust performance, the H1-1 was well-suited for a range of demanding applications. These included commercial algorithms requiring high accuracy, complex quantum chemistry simulations, and various optimization problems where the ability to run deep circuits reliably was critical. Its capabilities also made it valuable for exploring fault-tolerant algorithms and fundamental quantum research.