Quantinuum's Helios Sets a New Accuracy Watermark: 98 Qubits, All-to-All Connectivity and Why That Matters More Than the Headline Number

[Cheeky Blake]

A paper published in Nature this week describes Helios, the new trapped-ion quantum computer from Quantinuum, as a 98-qubit processor with error rates and performance that push beyond what classical machines can easily simulate. The qubit count alone is notable, nearly double the 56 qubits of the previous record holder, Quantinuum's own System Model H2. But the more important story is accuracy rather than scale. The paper reports an average single-qubit gate error rate of about 2.5 in 100,000 and a two-qubit gate error rate of about 7.9 in 10,000, putting Helios among the best demonstrations recorded anywhere, comparable to Oxford's own world record of around 5 in 10,000.

The distinction matters because quantum operations are cumulative. A useful algorithm might require thousands or millions of operations chained together, and a small error rate per operation compounds quickly across a long calculation. Lower error rates mean more complex, more meaningful calculations become possible before the quantum information collapses. Helios also features all-to-all connectivity, meaning any qubit can in principle interact directly with any other rather than only its nearest neighbours, a property especially valuable for algorithms whose interaction patterns do not map neatly onto a fixed grid.

The hardware achieving this uses barium ions held in a quantum charge-coupled device architecture, essentially a tiny railway system where ions are stored in memory regions and physically shuttled into operation zones for laser-controlled quantum gates to be performed. Software makes real-time decisions about ion routing and gate ordering as a program runs, a sign that trapped-ion quantum computing is maturing from impressive laboratory components into something closer to a full computing system. The paper also reports Helios can run random circuit sampling tasks that are extremely difficult for classical machines to simulate, an important complexity benchmark, though distinct from solving an actually useful problem in chemistry, materials science or logistics.

The Conversation: A New Quantum Computer Sets a High Watermark For Accuracy - Are We on The Verge of a Big Breakthrough?thequantuminsider.com