#quantumvolume

Describe Quantum Volume.

IBM created Quantum Volume to measure quantum computers' true processing capacity. Unlike qubit counts, this metric considers hardware connections, error rates, and software compiler efficiency to assess performance. Finding the largest square circuit a machine can continuously operate yields an exponential number.

The Heavy Output Generation test ensures a device produces useful results rather than random noise. Despite application-specific workload constraints, it is a key industry benchmark for evaluating quantum computers' computational power. The paper stresses that hardware quality and durability, not scale, drive innovation.

Why Quantum Volume is the New Standard for Supercomputing Power in the Quantum Space Race Early in the quantum revolution, the industry sought qubit count. Tech businesses talked about 50, 72, or 100 qubit systems as if they were the only success factor. But as the field evolves in 2026, experts have found that outstanding performance doesn't always require many qubits.

If qubits are “noisy,” error-prone, or poorly linked, they cannot perform complex instructions. This revelation encouraged the industry to adopt Quantum Volume (QV), a more complete performance measure.

Beyond the Data: Orchestra Comparison

Professionals often utilize music to show why raw qubit figures are misleading. If qubit count matches the number of musicians on stage, a group can perform a difficult symphony without mistakes.

Ten world-class violinists are better than 100 non-players. Quantum volume considers qubit quality, gate fidelity, and coherence time.

Quantum Volume formula

Quantum Volume, a single benchmark figure representing actual capabilities, was introduced by IBM. It is measured using a “square” random quantum circuit with equal qubits (width) and operational steps (depth).

QV = 2k

Where k is the greatest number of qubits that may complete a square circuit, the simple yet effective formula is utilized.

To pass a test, the quantum computer must produce “heavy” outputs with a probability at least two-thirds higher than random guessing. A machine with a k-value of 10 maintaining a 10x10 circuit but failing at 11x11 has a Quantum Volume of 210, or 1,024.

How to Determine High Score?

High Quantum Volume is system-level, not hardware-level. Several aspects must work well together to boost the score:

Gate Fidelity: High error rates quickly impair calculations as the circuit deepens.

Connectivity is how easily qubits can "talk" across the semiconductor. Systems having “all-to-all” connectivity, such trapped-ion systems, perform better because they do not require additional “SWAP gates” that create errors.

Compiler efficiency depends on software stack. Intelligent compilers can enhance hardware performance by optimizing code for fewer steps.

Record and Competition Scene 2026

The quest for the largest Quantum Volume has become a high-stakes “space race” between technologies.

Trapped-ion systems lead this category. The company Quantinuum established a record of over 33.5 million quantum volumes in early 2026. Their H-Series systems, which reached 225 in September 2025, break records.

In the meantime, IBM advances superconducting technology. Their Heron r3 “Pittsburgh” system had 211 (2,048) QV in August 2025. Although easier to grow to huge qubit counts, superconducting devices often have more connectivity difficulties than trapped-ion devices.

Classical Simulation “Wall”

Quantum volume is approaching a fundamental limit despite its utilization. To validate a QV score, a traditional supercomputer must reproduce the circuit to verify the quantum machine's response.

After 50 qubits, ordinary computers cannot keep up with the simulation. The “proof” of scores for massive systems is nearly impossible. Layer Fidelity and CLOPS (Circuit Layer Operations Per Second) are being prioritized for the next generation of 1,000+ qubit CPUs.

The Future of Benchmarking

Although flawed, it uses fake random circuits instead of application workloads. Quantum Volume remains the most reliable indicator of progress in the NISQ era. Engineers are encouraged to build balanced machines rather than huge ones and loud systems are penalized.

A Major Advance in Diamond-Based Quantum Computing: Room-Temperature NV Center Register Benchmarked at Quantum Volume 8

A team of scientists estimated and measured the quantum volume of a nitrogen-vacancy (NV) center-based quantum record in diamond, a huge advance in solid-state quantum technology. The study is a major step toward establishing that room-temperature quantum hardware can perform as well as top quantum systems.

Innovation in Room-Temperature Hardware

The paper addresses one of quantum information science's most difficult problems: accurately measuring hardware performance for direct comparison across physical architectures. Researchers from the Max Planck Institute for Solid State Research and Stuttgart University lead it. The unusual properties of diamond NV centers allow this register to function at ambient temperature, unlike many quantum computers that use superconducting circuits or trapped ions.

The group evaluated single-qubit register performance and created a detailed connection map. The study found that the register's all-to-all connectivity enabled 2- and 3-qubit gate performance, which was “promising and competitive”. Since it simplifies quantum computations, this high degree of connection is an advantage over systems with more limited qubit interactions.

Quantum 8: Success Measurement

Researchers measured the NV core register's processing power using Quantum Volume (QV). Quantum volume is a comprehensive statistic that considers gate integrity, connectivity, and qubit count to calculate device power.

The team experimentally calibrated a register error model using randomized benchmarking, a sophisticated quantum gate reliability method. This model yielded 8 quantum volumes for the register. While this figure may seem small compared to the largest superconducting arrays, it allows the “unification of different architectures” and the assessment of joint metrics throughout the sector at room temperature using high-fidelity multi-qubit gates.

Competence in Collaboration

The study was a partnership between experts from top colleges. Tom Jäger, MinSik Kwon, Max Keller, and Rouven Maier from the University of Stuttgart performed the key testing and developed the software architecture. Joining them were document writer Vadim Vorobyov and general supervisor Jörg Wrachtrup.

International and cross-sectoral collaboration. Nicholas Bronn of IBM Quantum created a noisy simulator to simulate hardware limits and provided benchmarking recommendations. Regina Finsterhoelzl and Guido Burkard of Konstanz University enhanced this simulator. Leon Büttner, Rebekka Eberle, and Daniel Hähnel of the Fraunhofer Institute for Applied Solid State Physics (IAF) measured the register's performance.

(NV centers, defects in the diamond lattice where a nitrogen atom replaces a carbon atom next to a vacancy, are well known in science and not exclusively obtained from these sources, but the sources attest to their use as the foundation for the quantum register.)

Disclosure and Data Access

The researchers published their data on the DaRUS repository in accordance with open-science standards. The authors also make the computer code used to simulate quantum volume measurement available upon reasonable request so other scientists can replicate and expand on their discoveries. This openness is considered to enable the abstract's “unification” of quantum hardware benchmarks.

The initiative received major funding from the EU Horizon initiative SPINUS and the Land Baden-Württemberg's QC4BW and KQCBW24 programs.

Future View

The conclusions of this work may influence future solid-state quantum processor evaluations. The researchers showed that room-temperature NV centers may be benchmarked using Quantum Volume, bringing diamond-based quantum computing closer to the mainstream discourse dominated by cryogenically cooled devices.

NV center registers can function at room temperature without compromising the “all-to-all” connectivity needed for complex gates, making them a key component of some quantum applications, especially those that require portability or integration with current infrastructure.

What's quantum volume?

Quantum volume is used to evaluate a quantum computer's performance and capability beyond qubit count.

Quantum volume evaluates a quantum system's ability to successfully execute complex quantum circuits rather than a single factor.

A Simple Definition

QV measures the size and depth of a quantum circuit a quantum computer can perform exactly before errors overwhelm it.

Helios

A next-generation trapped-ion quantum computer, Quantinuum's H-Series is called the "Helios Quantum." In 2025, it will launch as a full-stack platform to set a new standard.

How Helios Works

Helios Quantum qubits are trapped ions. Process has numerous steps:

Trapping the Ions: In a vacuum container, electric and magnetic fields separate ions from their surroundings.

Creating Qubits: Trapped ions' intrinsic energy states are represented by ∣1⟩ and ∣0⟩ as qubits.

Qubit control: Lasers control ion states. Laser pulses compute using quantum logic gates like Hadamard and CNOT Gates.

Lasers also enable ion state entanglement, which allows complex multi-qubit computations.

The ions are measured using a laser. The ultimate quantum state depends on glow.

Quantum Helios Features and Functions

For scalability and performance, Helios Quantum has several key components:

Due to their expanding number of qubits, quantum computers with high qubit counts have improved processing capacity.

Precision laser control and a clean environment provide the Helios Quantum system remarkable gate fidelity, or low error rates.

Trapped-ion systems may entangle any qubit with any other, which is extremely useful. Avoiding “qubit swapping” simplifies quantum circuit design and improves performance.

Qubit count, connectivity, and gate quality are utilised to benchmark Helios Quantum. Helios' high Quantum Volume allows it to run more complex algorithms. May 2025 saw a record Quantum Volume of 8,388,608 (2^23) for Quantinuum's old system, H2.

New Software Stack Integration

New software stack integration Together with Helios Quantum, a new software stack will remove access hurdles, speed up solutions, and improve user experience. The updated stack has:

Guppy, a new, open-source programming language, is based on Python, a popular classical computing language. Gate-by-gate development is arduous and error-prone, whereas Guppy treats quantum programs as dynamic, organised software. It supports real-time feedback and ‘if’ statements and ‘for’ loops.

Helios-simulating open-source emulator Selene. Selene is Helios' "digital sister," containing its advanced runtime features like hybrid quantum-classical logic and measurement-dependent control flow. It executes Guppy programs out of the box, so developers can build and test without hardware access. Selene hosts cuQuantum and NVIDIA GPU simulation backends.

Helios and third-party devices are still accessible by default on Quantinuum's cloud-based SaaS platform. Updated Nexus supports Guppy and Selene. In a cloud-native SaaS full-stack system, it connects all stack components. This platform allows collaboration, Guppy program management, and results analysis.

TKET: TKET, a middleware technology for quantum software applications, will henceforth only be used as a compiler toolchain and for Guppy program optimisation.

With Nexus and Selene supporting Quantum Intermediate Representation (QIR), users can program in their favourite languages like NVIDIA CUDA-Q, Microsoft Q#, and ORNL XACC.

Advantages of Helios Quantum

Users can benefit from Helios Quantum and its revolutionary software stack in many ways.

With Guppy's Python basis, more developers can use quantum programming.

The integrated stack, real-time control, and powerful algorithms speed up time-to-solution.

Improvements in Quantum Error Correction (QEC): Guppy's adaptive technique allows developers to apply quantum teleportation and magic state distillation codes. Modularity accelerates fault-tolerance. The stack supports atypical QEC and NVIDIA CUDA-QX.

The Helios' next-generation control system and groundbreaking real-time engine allow quantum measurements to dynamically steer activities. Adjustable, fault-tolerant algorithms and scalability from thousands to millions of qubits require this.

Reduced Memory Error: Utility-scale algorithms and quantum error correction benefit from reduced memory error.

Trapped ions' strong isolation from ambient noise allows them to maintain their quantum state for longer periods of time, allowing longer algorithm execution.

Helios Quantum Uses

Helios' all-to-all link and high-fidelity qubits allow it to be utilised for:

Chemists and materials scientists simulate chemical interactions to create new batteries, catalysts, and drugs.

Risk analysis and portfolio optimisation using complex financial modelling simulations.

Supply chain management and vehicle routing are difficult optimisation problems.

Simulating chemical processes and protein folding speeds drug discovery.

Helios Quantum cons

Helios and other trapped-ion devices have problems despite benefits:

Building and maintaining the hardware, which involves powerful lasers, complex suction systems, and cutting-edge cooling technologies, is tough and expensive.

Speed: Trapped-ion quantum gates are slower than superconducting quantum computers.

Even with all-to-all communication, capturing and maintaining a large number of ions in a single system makes high-scale production problematic.

Helios Quantum Prospects