That depends on who you ask. The dream scenario, which a number of companies are investing heavily in pursuing, is to supercharge the current generation of cloud computing platforms run by Microsoft, Google, Amazon and IBM using quantum computers to offer computer capacity outstripping the world’s fastest classical supercomputers.

Sitting in carefully controlled refrigerated data centres around the world, quantum computers would be sent complicated tasks via the internet, putting computing power in the hands of users that was previously only available to the world’s top research labs.

Indeed that type of cloud-based quantum processing is already available to some degree for specialist uses. 

Breakthroughs in the world of quantum computing are also coming thick and fast. Last year I reported on how Google scientists claimed to have achieved “quantum supremacy” when they completed a mathematical test in 200 seconds that they estimate would have taken the world’s fastest supercomputer 10,000 years to figure out.

But huge barriers have to be overcome before quantum computers are shouldering the computing load for a wide range of tasks across multiple industries.

Er, what is quantum computing?

First, we should re-cap exactly what quantum computing is. If regular computers store and transfer data as 1s and 0s (bits), quantum computers store them as ‘qubits’, bits of quantum information. 

The main difference is that quantum computers exploit the phenomenon of superposition, which allows for qubits to be in multiple physical states at the same time. It is a bit like a coin with heads on one side and tails on the other. When the coin is spinning, it appears to be in the position of heads and tails at the same time, or in data terms, zero and one simultaneously.

This is a mindblowing aspect of quantum physics that lets you exploit superposition to exponentially increase the amount of data that can be processed by a quantum computer at any given time. As more qubits are added to the mix, the potential for undertaking simultaneous equations increases exponentially.

Quantum computers are already being used for niche purposes in the world of materials research, pharmaceuticals, finance, design and chemical engineering. But as Google’s quantum hardware lead, Dr Anthony Megrant, told me last year, it is just a matter of time before quantum computers are used for everyday business computing tasks too.

“The main challenges towards even more applications is we need to grow the number of qubits and reduce the errors associated with each qubit,” says Megrant.

“There’s nothing fundamental stopping this scaling.”

But scaling how quickly? Many in the quantum field don’t expect significant uptake of quantum computing for at least a decade.

Quantum goes commercial

The start-ups working on the cutting edge of quantum research beg to differ. Last month, D-Wave Systems, a Canadian quantum computing start-up, unveiled what it claimed was the world’s most powerful quantum computer.

Advantage is “the first quantum computer built for business,” D-Wave added. Advantage makes available at least 5,000 qubits of quantum computing capacity to users. That’s up from 2,000 qubits with its predecessor. In computing terms, D-Wave claims it allows large computational problems with up to one million variables to be tackled.

But those users don’t simply buy a quantum computer and install it at their office. D-Wave’s Advantage computer uses a quantum processor that needs to be kept at a temperature near absolute zero and isolated from the surrounding environment for the quantum mechanics to work. It sits in a cryogenic chamber.

While the company started out selling earlier versions of its computers, it now operates them itself and rents access to them via its Leap quantum cloud service. It also has a partnership with Amazon Web Services to allow Amazon users access to Advantage via the Braket service. You can now have a quantum computer work on your complicated computing projects – here’s the pricing. Microsoft has a similar service on offer in Azure Quantum. 

“You know, the notion that it’s ten years before we can get to commercial applications, it’s just a fallacy,” D-Wave CEO and president Alan Baratz told last month’s Tech Crunch Disrupt 2020 conference.

D-Wave’s Advantage quantum computer

“We will have customers standing up and talking about real commercial applications that they are using in production with the system.”

What types of applications exactly? Baratz says D-Wave’s system excels at handling optimisation problems.

“Protein folding and packaging is an optimisation problem. Understanding how to allocate resources across hospitals is an optimisation problem,” he points out.

Many business challenges are simply optimisation problems of one sort or other.

“Even if we can deliver 100 x performance improvement [over classical computers], that’s real value to an end customer on our path to one million x, and beyond.”

US quantum computing company IonQ is also serving customers with cloud-based quantum processing now, but has taken a different path with its technology. For its computer, it uses trapped ions, or charged atomic particles that are suspended in space with electromagnetic fields.

Peter Chapman

“Trapped ions use the technology from atomic clocks which have been around for quite a long time,” says Peter Chapman, CEO and president of IonQ, who also spoke at Tech Crunch Disrupt.

“It’s a technology that is easier to build, less sensitive to noise and errors, and we did this because we wanted to get quantum computers out into the hands of developers to use as quickly as possible,” he said.

Quantum on the desktop

IonQ this month released what it claimed is the world’s most powerful quantum computer, using a different benchmark. It wants to make its quantum processing available to customers to solve complex problems in areas such as chemistry, medicine, finance and logistics.

Interestingly, without the need for IonQ’s equipment to be chilled to outrageously low temperatures, Chapman sees trapped ion quantum computers as portable units making their debut within five years.

“We’re building a prototype right now which is, except for the laser, less than a square foot in its entirety,” he said. 

“You’ll see quantum computers which are now starting to look like desktop PCs.”

That, says Chapman, will be crucial for complex computing jobs where connecting continuously to the cloud isn’t an option, such as for military uses on fighter aircraft. Other edge computing uses will also emerge, he adds.

Two big problems remain in improving the performance of quantum computers, Chapman added – making qubits and controlling them to work on computational problems. Quantum computers are also less precise in delivering answers than our existing computers. But he described these as problems that can be worked on incrementally, the scientific breakthroughs have already been achieved.

Still, the technology is notoriously sensitive and quantum programmers are constantly working to reduce errors. Design of quantum algorithms to run on these computers is still an emerging field.

Getting up to speed

The bottom line is that quantum computing, now available in a limited capacity as a cloud computing service, should be on the radar of businesses in science, engineering, medicine, design and other industries where complex computation is involved.

“The potential is so great, and the technological advances are coming so rapidly, that every business leader should have a basic understanding of how the technology works, the kinds of problems it can help solve, and how she or he should prepare to harness its potential,” consultants at McKinsey advised earlier this year.

It is in the world of chemical engineering and drug development that quantum computing is perhaps most sought after currently. As McKinsey explains, enzymes are so complex that it is virtually impossible for classical computers to model them.

“A sufficiently powerful quantum computer, however, could accurately predict in a matter of hours the properties, structure, and reactivity of such substances—an advance that could revolutionize drug development and usher in a new era in healthcare” says McKinsey. 

Research from McKinsey

“Quantum computers have the potential to resolve problems of this complexity and magnitude across many different industries and applications, including finance, transportation, chemicals, and cybersecurity.”

For more general business applications, classical computers will continue to add more value as they become more powerful and machine learning and neural networks become more sophisticated.

The true advances of quantum computing will not simply be about offering more computing capacity faster, but taking advantage of the quantum world and algorithms designed specifically for it, to compute in ways existing computers simply can’t. That’s when we can put them to work tackling the world’s most challenging problems.