Qh21

Quantinuum H2-1: A High-Fidelity Trapped-Ion Quantum Processor

Quantinuum H2-1 Commercial QPU

The Quantinuum H2-1 system offers 56 physical qubits with all-to-all connectivity, setting a high bar for fidelity and demonstrating significant progress towards fault-tolerant quantum computing.

Quantinuum Trapped-ion Commercial QPU Physical qubits public access confidence: high

As a data analyst evaluating the landscape of quantum computing hardware, the Quantinuum H2-1 system stands out as a significant commercial offering. Developed by Quantinuum, this trapped-ion quantum processing unit (QPU) represents a mature and highly capable platform. Its core strength lies in its 56 physical qubits, a substantial number for current-generation systems, especially when coupled with its unique architecture and impressive performance metrics. The H2-1 is not merely a research prototype; it is a commercially available QPU, accessible through various cloud platforms, indicating its readiness for real-world application and exploration by researchers and enterprises alike.

The choice of trapped-ion technology by Quantinuum is a strategic one, known for its inherent advantages in qubit coherence and connectivity. Unlike some other quantum modalities, trapped ions typically offer longer coherence times and the ability to implement all-to-all connectivity, which significantly simplifies algorithm design and reduces compilation overhead. The H2-1 leverages a 'racetrack trap' design, a sophisticated engineering solution that allows for the precise manipulation and transport of individual ions. This design is crucial for scaling up the number of qubits while maintaining high-fidelity operations, addressing one of the most persistent challenges in quantum hardware development. The hyperfine states of these ions serve as the qubit basis, providing robust and well-isolated quantum states.

A key differentiator for the H2-1 is its all-to-all connectivity, achieved through the transport of ions within the racetrack trap. This means any qubit can interact directly with any other qubit, a feature that is highly desirable for executing complex quantum algorithms without the need for costly SWAP gates or ancillary operations that can degrade overall circuit fidelity. For a data analyst, this translates directly into more efficient algorithm mapping and potentially deeper, more complex circuits that can be run reliably. This architectural choice positions the H2-1 as a versatile tool for exploring a wide range of quantum applications, from optimization problems to quantum chemistry simulations.

The system's performance is underscored by impressive benchmarks, including achieving a Quantum Volume (QV) of 33 million in 2023. Quantum Volume is a holistic metric that assesses a quantum computer's effective computational power, taking into account both the number of qubits and their error rates. A high QV indicates a system capable of running more complex circuits with greater reliability. Beyond QV, the H2-1 has demonstrated the execution of 56-qubit QAOA (Quantum Approximate Optimization Algorithm) circuits and pioneering work in fault-tolerant teleportation, showcasing its capabilities for both near-term heuristic algorithms and foundational elements of future fault-tolerant quantum computing. These achievements highlight Quantinuum's commitment to pushing the boundaries of quantum performance and reliability, making the H2-1 a compelling platform for advanced quantum research and development.

From a practical standpoint, the H2-1 is designed for accessibility and robust operation. Its availability through major cloud providers like Azure, alongside direct access options and partnerships such as ORNL QCUP, broadens its reach to a global user base across the US and EU. The support for popular SDKs like Qiskit, Cirq, and TKET further lowers the barrier to entry for developers and researchers already familiar with these programming environments. This combination of advanced hardware capabilities, strong performance metrics, and broad accessibility makes the Quantinuum H2-1 a critical system for anyone looking to engage with high-performance quantum computing today and to explore its potential for finance, logistics, chemistry, and beyond.

Key metrics

Physical qubits
56 (2024)
Number of fully connected ions
Benchmark headline
33
QV 33M (2023) | 56-qubit QAOA | Fault-tolerant teleportation
Error-correction readiness
0/100
Heuristic score from topology + mode + error hints
Historical importance
0/100
Heuristic score from milestones + roadmap language
Native gates
RX RY RZ | ZZ | Arbitrary ZZ
Gate alphabet you compile to
Connectivity
All-to-all via transport
Mapping overhead + routing depth sensitivity

Technical specifications

Spec Details
System ID QH21
Vendor Quantinuum
Technology Trapped-ion
Status Commercial QPU
Primary metric Physical qubits
Metric meaning Number of fully connected ions
Qubit mode Racetrack trap, hyperfine states
Connectivity All-to-all via transport
Native gates RX RY RZ | ZZ | Arbitrary ZZ
Error rates & fidelities 1Q infidelity 3e-5 typical (2025) | 2Q 1e-3 | SPAM 1e-3 | Memory 2e-4
Benchmarks QV 33M (2023) | 56-qubit QAOA | Fault-tolerant teleportation
How to access Subscription clouds
Platforms Azure | Direct | ORNL QCUP
SDKs Qiskit Cirq TKET
Regions US EU
Account requirements Subscription
Pricing model Subscription
Example prices Azure 135k/mo HQC
Free tier / credits Research credits
First announced 2023-05-09
First available 2023
Major revisions Expanded to 56 qubits (2024)
Retired / roadmap Active, roadmap to Helios 2025
Notes Racetrack enables better scaling

System profile

The Quantinuum H2-1 system presents a compelling profile for data analysts and quantum developers, characterized by its robust trapped-ion architecture and high-fidelity operations. Understanding these capabilities is crucial for assessing its suitability for specific computational tasks and for comparing it against other quantum hardware modalities.

Qubit Architecture and Connectivity

At the heart of the H2-1 lies its 56 physical qubits, implemented using the hyperfine states of trapped ions. This number represents a significant scaling achievement within the trapped-ion paradigm, offering a substantial computational space for complex problems. The system employs a sophisticated racetrack trap design, which is not just an engineering marvel but a critical enabler for scalability. This design allows for the individual manipulation and transport of ions, facilitating dynamic reconfiguration of qubit interactions. The most impactful feature stemming from this architecture is its all-to-all connectivity via transport. This means any qubit can be brought into interaction with any other qubit on demand. For a data analyst, this is a game-changer: it drastically simplifies the process of mapping quantum algorithms onto the hardware, as there's no need to optimize for limited nearest-neighbor connections. This reduces the number of SWAP gates required, which are typically error-prone and consume valuable circuit depth, thereby improving overall circuit fidelity and execution speed. The ability to perform arbitrary two-qubit gates between any pair of qubits unlocks the full potential of many quantum algorithms that require dense connectivity, such as those found in quantum chemistry or complex optimization problems.

Native Gate Set

The H2-1 supports a universal set of native gates, including single-qubit rotations RX, RY, RZ, and two-qubit entangling gates ZZ and Arbitrary ZZ. The availability of arbitrary ZZ gates is particularly powerful, as it allows for fine-tuned control over the strength and duration of entangling operations, which can be beneficial for optimizing specific algorithm implementations. This comprehensive gate set ensures that the H2-1 can execute any quantum algorithm, providing the foundational building blocks for universal quantum computation. For users, this means flexibility in translating theoretical quantum circuits into executable code without significant overhead from gate decomposition.

Error Rates and Fidelities

One of the H2-1's most impressive attributes is its exceptionally low error rates, which are critical for running deep quantum circuits reliably. The system boasts a typical 1-qubit infidelity of 3e-5 (0.003%), projected for 2025, which is among the best in the industry. This means that single-qubit operations are highly reliable. The 2-qubit infidelity stands at 1e-3 (0.1%), also a very competitive figure, indicating robust entangling operations. State Preparation and Measurement (SPAM) infidelity is reported at 1e-3 (0.1%), which is crucial for accurately encoding initial states and reading out final results. Furthermore, the memory infidelity is 2e-4 (0.02%), highlighting the excellent coherence properties of the trapped-ion qubits, allowing quantum information to persist for longer durations. These low error rates collectively enable the execution of significantly deeper and more complex quantum circuits before errors accumulate to render the computation meaningless. For a data analyst, these numbers directly translate to the effective 'depth' of algorithms that can be explored, pushing the boundaries of what's currently achievable on noisy intermediate-scale quantum (NISQ) devices.

Performance Benchmarks

The H2-1's performance is validated by several key benchmarks. It achieved a Quantum Volume (QV) of 33 million in 2023, a testament to its combined qubit count and low error rates. Quantum Volume is a hardware-agnostic metric that quantifies the largest random circuit of a certain depth that a quantum computer can successfully execute. This high QV indicates a powerful and reliable system. Beyond this, the H2-1 has successfully executed 56-qubit QAOA (Quantum Approximate Optimization Algorithm) circuits, demonstrating its capability for tackling complex optimization problems at scale. The system has also been instrumental in pioneering demonstrations of fault-tolerant teleportation, a foundational primitive for future error-corrected quantum computers. These benchmarks collectively showcase the H2-1's prowess in both near-term applications and its potential for advancing towards fault-tolerant quantum computing.

System Limits and Operational Characteristics

The H2-1 offers practical advantages in its operational limits. Users benefit from unlimited shots, allowing for extensive statistical sampling to mitigate noise and improve result confidence. The system supports circuits with thousands of gates in depth and duration, a direct consequence of its high fidelities and coherence times. This capability is essential for exploring more sophisticated algorithms. Queue times are typically minimal, often less than 10 minutes, ensuring efficient access for users. Furthermore, the system exhibits very low crosstalk, at 5e-6 (0.0005%), which is critical for maintaining the integrity of parallel operations across multiple qubits, preventing unintended interactions that can introduce errors.

Trade-offs and Use Cases

While trapped-ion systems like the H2-1 offer superior fidelity and all-to-all connectivity, they are generally slower than superconducting qubit systems in terms of gate speeds. However, this trade-off is often acceptable given the significantly better fidelity, which allows for deeper circuits and more reliable results. The H2-1's architecture is based on the Quantum Charge-Coupled Device (QCCD) scalable paradigm, indicating a clear path towards further scaling up qubit numbers while maintaining performance. The system is well-suited for a variety of applications, including complex simulations in finance, logistics, and chemistry, where high fidelity and connectivity are paramount. It is also an excellent platform for fault-tolerant demonstrations and scaling tests, pushing the boundaries of quantum error correction and larger-scale quantum algorithms.

Generation lineage (family-level)
Heuristic chain based on common naming. Verify by revision/date for strict claims.
Related systems (same vendor)
Cross-system comparison (same vendor)
System Status Primary metric
Quantinuum H3 Commercial QPU Physical qubits: 98 (2025)
Quantinuum H1-1 Superseded commercial QPU Physical qubits: 20 (2022)
Quantinuum H1-2 Superseded commercial QPU Physical qubits: 20 (2022)

Access & pricing

How you access it
  • Public access is available through commercial channels.
  • Access is primarily via subscription-based cloud platforms.
  • Available on major platforms including Azure Quantum, direct access from Quantinuum, and through partnerships like ORNL QCUP.
  • Geographic availability spans both the US and EU regions.
  • Supports popular quantum SDKs: Qiskit, Cirq, and TKET, facilitating broad developer adoption.
  • Account requirements typically involve a subscription or research agreement.
  • Offers flexibility with both cloud-based and potential on-premise deployment options for specific partners.
How costs sneak up
  • Public pricing information is available, indicating transparency in cost structures.
  • The primary pricing model is subscription-based, often tailored to usage tiers.
  • Example pricing, such as Azure's 135k/month for HQC (High-Performance Quantum Computing), provides a reference point, though this specific example is not independently confirmed.
  • Key cost drivers include the number of shots executed and the total gate operations performed.
  • Research credits and specific free tiers may be available for academic or exploratory projects.
  • Pricing notes indicate a 'pay per use' component within the subscription model, allowing for scalable consumption.

Status timeline

The Quantinuum H2-1 system has a dynamic and progressive development timeline, marked by significant milestones that underscore its rapid evolution and increasing capabilities. Understanding this timeline is crucial for appreciating the pace of innovation in trapped-ion quantum computing and Quantinuum's strategic roadmap.

The H2-1 was first announced on May 9, 2023, marking its official introduction to the quantum computing community. This announcement generated considerable interest, signaling a new era for commercial trapped-ion systems with enhanced qubit counts and performance. Following its announcement, the system became first available commercially in 2023, allowing early adopters and researchers to begin leveraging its capabilities almost immediately. This swift transition from announcement to commercial availability highlights Quantinuum's operational maturity and readiness to deliver advanced quantum hardware.

A significant major revision occurred in 2024, expanding the system to 56 qubits. This expansion was a critical upgrade, substantially increasing the computational power and complexity of problems the H2-1 could address. For a data analyst, this qubit scaling is a direct indicator of the system's growing capacity to tackle more challenging quantum algorithms and explore larger problem instances. Such an upgrade demonstrates a commitment to continuous improvement and a clear path towards higher qubit counts, which is essential for advancing quantum computing beyond the NISQ era.

The H2-1 is currently active and is a central component of Quantinuum's ongoing quantum hardware strategy. The roadmap indicates a clear progression towards future generations, with plans for the successor system, Helios, slated for 2025. This forward-looking roadmap suggests that Quantinuum is not resting on its current achievements but is actively pursuing further advancements in qubit count, fidelity, and overall system performance. The continuous development and planned upgrades provide confidence in the long-term viability and competitiveness of Quantinuum's trapped-ion technology. For users, this means investing in a platform that is not only powerful today but also has a clear and ambitious trajectory for future enhancements, ensuring that their research and development efforts remain at the forefront of quantum innovation.

What to verify next

  • Investigate the latest reported fidelity metrics, especially for 1-qubit and 2-qubit gates, as these are continuously improving.
  • Look for new demonstrations of logical qubit operations or early fault-tolerant protocols, as these indicate progress towards error correction.
  • Monitor updates on the roadmap to Helios (2025) for details on qubit count, architecture, and expected performance improvements.
  • Examine case studies or benchmarks specific to your application domain (e.g., finance, chemistry) to assess practical performance.
  • Review any new publications or whitepapers from Quantinuum or independent researchers utilizing the H2-1 system.
  • Compare the H2-1's performance and cost-effectiveness against other leading quantum hardware platforms as new benchmarks emerge.

FAQ

What is the primary technology behind the Quantinuum H2-1?

The Quantinuum H2-1 utilizes trapped-ion technology, where individual atoms are suspended and manipulated by electromagnetic fields. These ions' internal energy states serve as the qubits, offering high coherence and excellent control fidelity, which are critical for reliable quantum computation.

What does 'all-to-all connectivity' mean for quantum algorithms?

All-to-all connectivity means that any qubit in the system can directly interact with any other qubit. This is a significant advantage because it simplifies the mapping of quantum algorithms onto the hardware, reducing the need for 'SWAP' gates that move quantum information around. Fewer SWAP gates lead to shallower circuits, lower error accumulation, and more efficient execution of complex algorithms, especially those requiring dense entanglement patterns.

How does the 'racetrack trap' design contribute to the H2-1's capabilities?

The 'racetrack trap' is an advanced ion trap architecture that allows for the physical transport of individual ions (qubits) within the trap. This dynamic movement is key to achieving all-to-all connectivity and scaling the system to a larger number of qubits while maintaining high-fidelity operations. It enables flexible qubit-qubit interactions and efficient parallel processing.

What is Quantum Volume, and why is 33 million significant for the H2-1?

Quantum Volume (QV) is a benchmark metric that measures the effective computational power of a quantum computer, considering both the number of qubits and their error rates. A QV of 33 million (achieved in 2023) for the H2-1 is highly significant because it indicates the system's ability to execute complex random circuits with a high degree of fidelity, showcasing its robust performance and reliability for a wide range of quantum tasks.

What are the typical error rates for the H2-1, and what do they imply?

The H2-1 boasts very low error rates: 1-qubit infidelity of 3e-5 (typical for 2025), 2-qubit infidelity of 1e-3, SPAM (State Preparation and Measurement) infidelity of 1e-3, and memory infidelity of 2e-4. These low error rates are crucial because they allow for the execution of much deeper quantum circuits before errors accumulate to render the results unreliable. This directly translates to the ability to run more complex and meaningful quantum algorithms.

What kind of applications is the Quantinuum H2-1 best suited for?

Given its high fidelity, all-to-all connectivity, and growing qubit count, the H2-1 is well-suited for applications in areas like finance (e.g., portfolio optimization, risk analysis), logistics (e.g., supply chain optimization), and chemistry (e.g., molecular simulation, materials science). It's also an excellent platform for demonstrating fault-tolerant quantum computing primitives and for general scaling tests of quantum algorithms.

How does the H2-1 compare to superconducting quantum computers?

The H2-1, being a trapped-ion system, typically offers significantly better qubit fidelity and all-to-all connectivity compared to most superconducting systems. However, superconducting qubits generally have faster gate operation speeds. The trade-off is often between speed and fidelity; the H2-1 prioritizes high fidelity and connectivity, enabling deeper and more reliable circuits, albeit at potentially slower individual gate times.



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