Forrest Hubert adjusts a sliver of silicon in a lab at Sandia National Laboratories, guiding laser light through a microscopic waveguide—part of a quiet revolution unfolding in the high desert of New Mexico. There, a partnership between Sandia and quantum computing company Quantinuum has achieved a milestone in the pursuit of reliable quantum machines: the Helios 98-qubit system has demonstrated one- and two-qubit operations with fidelities of 99.9975% and 99.921%, respectively—among the highest ever recorded. These numbers aren’t just technical benchmarks; they represent critical progress toward quantum computers that don’t just work, but work consistently.
Quantum computing promises to solve problems beyond the reach of classical machines—from designing life-saving drugs to unlocking new materials for clean energy. But for decades, the field has been held back by fragility. Qubits, the building blocks of quantum systems, are notoriously error-prone, easily disrupted by heat, vibration, or even stray electromagnetic fields. That’s why fidelity—the accuracy of quantum operations—is more important than raw speed. As Robin Blume-Kohout of Sandia puts it, "The most important aspect of today's quantum computers is not speed, but reliability."
The results, published in Nature, come from Sandia’s rigorous assessment of Helios, Quantinuum’s largest commercial quantum computer to date. Using advanced benchmarking techniques, including a new method for evaluating mid-circuit measurements—nondestructive readouts essential for error correction—Sandia’s team provided an independent certification of Helios’ performance. This collaboration, sustained over four years under a Cooperative Research and Development Agreement, has helped refine the integrated photonics technology that underpins Helios. These photonic chips, engineered at Sandia’s Microsystems Engineering, Science and Applications complex, use light to control trapped-ion qubits with precision, offering a scalable, energy-efficient path forward.
The implications extend far beyond one machine. High-fidelity operations are the foundation of fault-tolerant quantum computing—the ultimate goal where systems can detect and correct their own errors, enabling long, complex calculations. Sandia, as the Department of Energy’s longest-running quantum research lab, plays a unique role: testing, validating, and pushing the limits of emerging technologies for national security, economic competitiveness, and scientific discovery.
With Helios now setting a new standard in reliability, the path toward practical quantum supercomputing feels less like speculation and more like inevitability. As Sandia’s Mike Descour noted, the lab is committed to accelerating this future—not in isolation, but through open collaboration with industry, universities, and other labs. The quantum era may still be unfolding, but its cornerstones are being laid, one high-fidelity qubit at a time.