Commercializing quantum computers step by step

Alpine Quantum Technologies in Innsbruck, Austria, spun off from the University of Innsbruck and the Austrian Academy of Sciences, Vienna, in 2018.

Quantum computers promise to outdo their conventional counterparts in a number of challenging tasks by exploiting some strange properties of the atomic world. Whether designing new materials, optimizing delivery logistics or developing drugs, these machines should, in principle, be able to perform calculations much faster than classical devices.

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Alpine Quantum Technologies (AQT), a start-up in Innsbruck, Austria that grew out of the University of Innsbruck and the Austrian Academy of Sciences in Vienna, is building computers that have the potential to do all of this and more. These computers are based on ion traps, which consist of arrays of single ions held in a vacuum by electric fields and manipulated by extremely short laser pulses. The AQT adopt this technology among the most advanced in the world. But the company’s scientists are clear that making a full-fledged quantum computer won’t be easy.

Unlike some rival companies, who are trying to offer a combination of hardware, software and applications, AQT focuses solely on the hardware. It sells individual components such as ion traps, laser stabilizers, and associated electronics to other researchers studying quantum phenomena, even developing their own ion trap quantum computers. (Another The Spinoff Prize 2023 finalist, Parity Quantum Computing, by contrast, sells designs for quantum computers that can be applied to any type of hardware, not just ion traps.)

Strange and delicate

Quantum computers derive their unique capabilities from counterintuitive phenomena. While units of data called bits in a standard digital device take the values ​​of 0 or 1, quantum bits or qubits can exist in what is known as a superposition of 0 and 1 at the same time. Furthermore, multiple qubits can be entangled such that their states are interdependent in a way that is not possible with everyday classical objects those larger than a few atoms. Taken together, superposition and entanglement allow a set of qubits to exist in all possible combinations of 0s and 1s simultaneously, which offers a potentially huge advantage in processing speed over today’s classical computers.

But with great power comes great fragility. Quantum states can be destroyed by even the smallest disturbance, including tiny amounts of heat or radio wave energy. So while qubits need to be manipulated to run quantum algorithms, they also need to remain as isolated from the outside world as possible.

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Physicists are trying to meet these conflicting goals by studying qubits made by a variety of quantum systems, including electric currents in superconducting circuits, the magnetic spin of electrons or atomic nuclei embedded in crystalline solids, and photons traveling around silicon circuits. . Each type of qubit has its pros and cons. The main advantage of ion traps is that they are relatively insensitive to noise. Their drawback is the cumbersome equipment required, including lasers and associated electronics.

However, no type of qubit can remain immune to noise as quantum computers get scaled up, says Thomas Monz, a quantum physicist at the University of Innsbruck and co-founder and CEO of AQT. The increase in the number of qubits, together with the number of processor operations (known as gates), makes it more likely that errors will creep into the calculations. The solution to this is error correction, which involves using multiple physical qubits to represent a single logical bit of data. That way, the value of those qubits can be compared, and the system can weed out those that succumb to noise.

But correcting errors is not cheap. Typically, it multiplies the number of qubits required for a given computation by several orders of magnitude, which means, says Monz, that at least a million qubits are likely needed to compete with classical computers. It is a far cry from the few dozen typical of the most advanced quantum computers.

He does it slowly

AQT emerged from nearly a quarter century of research into ion-trap quantum computing conducted at the University of Innsbruck by physicists Peter Zoller and Rainer Blatt, and later, Monz. As Monz recalls, researchers from other institutions often approached the group to ask if they could purchase ion traps and related accessories. Wanting to help but realizing, as Monz says, that he could not use Austrian taxpayer money to meet the demands, he set about preparing a financial plan. In 2018, the trio created AQT to sell their sought-after components, eventually aiming to build their own full-scale computer.

For Lieven Vandersypen, who is developing rival quantum dot qubits at Delft University of Technology in the Netherlands, this two-pronged approach makes sense. Selling the components generates income and puts them into a commercial mode of operation, he says, allowing researchers to work on the long-term challenges of a large-scale quantum computing system.

That long-term work is paying off. In 2020, Monz, Blatt and their colleagues reported how to fix a previously uncorrected type of error that can plague quantum computations the loss of a qubit in a register¹. They went on to demonstrate a complete set of gates that could be used to process qubits in a universal quantum computer². This device is capable of performing any type of calculation, both quantum and classical. They did this by intertwining two error-corrected logic qubits, the values ​​of which were each spread across seven ions (see Ion-trap quantum processor).

Despite this encouraging progress, the AQT team is determined to keep expectations in check. The company has successfully demonstrated several universal quantum computers, installed in industry-standard 19-inch racks, used for computer servers. Monz acknowledges that manufacturers of quantum computers often boast about the amount of qubits in their processors: US tech giant IBM, for example, announced plans for a computer with about 1,000 superconducting qubits this year. But Monz doesn’t want to play the numbers game. What really matters to him, he argues, is the quality of the qubits. If you want to make grappa, it makes no difference whether you have 10 or 100 bad apples, he says. You must start with 10 good apples.

The current version of the AQT computer comes in two forms: a system that has two high-quality error-corrected qubits, or a system with ten times that number of lower-quality qubits. Monz believes most clients will opt for the latter, which he says may still be suitable for tasks where errors aren’t very problematic, such as optimizing financial portfolios or analyzing logistical problems. There’s going to be this transition where everyone is initially going to work with faulty qubits and find use cases, he says. Only later, when the community has access to abundant error-corrected qubits, will we be able to achieve very high-precision quantum computing.

AQT has 20 employees and generated approximately 1 million (US$1.1 million) in sales in 2021, after selling its ion trap components to academic and industrial research groups in Europe, North America and Asia. It also offers access to its quantum computers remotely through the cloud or by installing them in customers’ labs. So far, however, it hasn’t sold any complete working systems.

AQT director of technology Juris Ulmanis explains that he and his colleagues are mindful not to overpromise, making sure the quantum bits and gates that make up their processors are as robust as possible before the devices are scaled up. You have to excite people and inspire them, but at the same time remain realistic about what’s possible, says Ulmanis.

Such cautious assessments also come from outside. Vandersypen, for example, points out that AQT’s strategy may have a flaw: Selling its components could give competitors an edge over the inner workings of the company’s technology.

Monz acknowledges this concern, explaining that he and his colleagues don’t sell everything they make. In fact, they keep at least some of their secret ingredients off the shelves. There’s still a lot of special sauce left, he says.