Helios 98-qubit – A new 98-qubit trapped-ion quantum computer called Helios—built by Quantinuum—shows unusually low error rates and all-to-all qubit connectivity, pushing beyond what classical computers can easily simulate and shifting the focus from qubit counts to qubit quali
When you walk into the laboratory in Broomfield, Colorado, the scene looks almost impossibly delicate: 98 atoms suspended in mid-air, held in place by electric fields and cooled to temperatures close to absolute zero.
Each atom is far smaller than anything the naked eye could ever see. Yet each one carries information in a form that doesn’t exist in classical physics. Together, they make Helios—a new quantum computer built by the British-American company Quantinuum.
Quantum computers promise power by using the rules of quantum mechanics, the physics of the atomic and sub-atomic world. Helios uses a setup known as trapped-ion, where information is encoded in the quantum states of ions.
In a paper published in Nature. Helios is described as a 98-qubit processor with very high accuracy and performance that pushes beyond what can easily be simulated on classical machines. That alone is a headline-worthy milestone. The harder question is what comes next: whether it is a better machine, not just a larger one.
Helios is built around 98 qubits, surpassing the previous biggest, System Model H2, which had 56 qubits. But the story turns on a more uncomfortable truth about quantum technology. Qubits aren’t like ordinary digital bits. They can exist in quantum states that don’t behave like the ones and zeroes of conventional computers.
That difference is what allows some calculations to be arranged in ways that may eventually outperform even the largest supercomputers. Possible applications range widely—from new materials and better optimisation methods to improved chemistry simulations and new approaches to cryptography.
Then comes the catch. Qubits are extremely fragile. Temperature variations. imperfect control. unwanted interactions with the environment—and in some systems. even moving information around the device—can all disturb them. In practice, the race in quantum computing isn’t only about collecting more qubits. It’s about producing more good qubits, controlled accurately enough to run long and meaningful calculations.
Helios’ result matters because it tackles both sides of that challenge at once: scale and precision. It’s not just that 98 qubits is relatively large. The Nature paper also reports very low error rates at that scale.
Errors are more common with quantum computers than with classical ones. and error correction is a big challenge in this area. The paper gives an average error rate for single-qubit gates of about 2.5 in 100,000 for Helios. For two-qubit gates—harder and more important for useful computation—the average error rate is about 7.9 in 10,000. The paper says this is similar to the best demonstrations of around 5 in 10,000 errors.
In a quantum computer, mistakes don’t stay small for long. Quantum operations are cumulative, and a useful quantum algorithm may require thousands, millions, or more operations. Lower error rates mean more complex calculations can be attempted before the quantum information falls apart.
Connectivity is the other place where Helios distinguishes itself. The machine uses all-to-all connectivity, meaning any qubit can in principle interact with any other.
In many quantum computers, qubits can interact only with their nearest neighbours. If two distant qubits need to work together, the information must move through a chain of intermediate steps. Each extra step adds time and introduces more opportunities for error. Helios avoids that constraint. which is especially valuable for algorithms whose interaction patterns don’t fit neatly onto a fixed grid.
The hardware behind Helios is built around charged atoms held and steered by electric fields. Trapped-ion computers like Helios use ions as qubits. They are manipulated with laser pulses, an approach known for high accuracy—but scaling it up while preserving that accuracy is technically difficult.
Helios uses barium ions in a quantum charge-coupled device (QCCD) architecture. A way to picture it is as a tiny quantum railway. Ions can be stored in memory regions and physically moved into operation zones when the computer program needs particular qubits for a calculation. In those operation zones. carefully controlled laser pulses perform the basic steps of quantum algorithms—quantum gates—changing a single ion’s quantum state or linking the states of two ions so the computer can process information.
In Helios, there’s a ring-shaped storage area and a junction that help route the ions around the device. Separating storage, movement, and computation isn’t just clever engineering. It signals that quantum computing is being shaped into something closer to a full computing system. not only a collection of impressive lab demonstrations.
There’s also software designed to make routing and control decisions while a program is running. In practice. it decides which physical ion should represent each qubit. which ions need to be moved into the operation zones. and the order in which quantum gates should be carried out. That matters for more advanced quantum programs—especially those where later steps may depend on measurements made during the computation.
The paper also reports that Helios can run random quantum circuits that would be extremely difficult to simulate on classical machines. Random circuit sampling is a benchmark for complexity and computational reach. But it isn’t the same as having a generally useful quantum computer. It doesn’t, by itself, solve problems in medicine, climate science, or engineering.
So how big an advance is this? Helios is serious because it brings scale, accuracy, connectivity, and programmability into one machine—even if it isn’t the arrival point of a quantum revolution.
It’s also a reminder of how transformative technologies tend to move. They rarely show up in a single leap. They get built step by step, atom by atom, until the impossible starts to look engineered.
Helios Quantinuum trapped-ion 98-qubit processor Nature paper quantum computing error rates all-to-all connectivity quantum charge-coupled device QCCD barium ions