In 2015 RBS was still deeply preoccupied with the task of patching up its balance sheet in the wake of the 2007/08 financial crisis and the huge government bailout that took a large chunk of the bank into public ownership. It’s fair to say that multimillion investments into risky technology start-ups were not common.

But the troubled bank felt it had to make an exception when it invested in Canadian quantum computing start-up 1Qbit. The decision that the bank almost had no choice but to invest was taken after a presentation in Silicon Valley attended by former chief executive Ross McEwan, current incumbent Alison Rose and John Stewart, the bank’s head of innovation.

Mr Stewart recounted for the Sunday Times:

“I was watching Ross and [current chief executive] Alison Rose and their jaws were on the floor. Ross said, ‘We need to get all over this. More people in the bank need to know. What do we need to do?’ ”

The investment was made and now, five years later the bank has doubled down through participation in 1Qbit’s most recent investment round. But what is it that convinced a bank that was, and largely still is, conservative when it comes to investing major sums in the tech start-up scene? Especially outside of the UK.

Andrew Furman, 1Qbit’s co-founder, captured the RBS team’s imagination with their illustration of how quantum computing will one day, within the next twenty years with some projecting ten, radically change every single industry in the world. Including banking.

Quantum computing is based on qubits, rather than the bits that are the foundation of traditional computing. Bits, electrical pulses that represent either a 1 or 0, have been the basic building blocks of computing since the very first computers. As much as processors and other computing technology has improved over the years, that has never changed.

Qubits, on the other hand, are sub-atomic particles such as photons or electrons which can, thanks to quantum mechanics, hold two states at the same time. That means each qubit can simultaneously represent both a 1 and a 0. That allows for exponentially faster computing power than even today’s bit-based supercomputers are capable of.

The technology needed to maintain sub-atomic particles as qubits is still nascent and the next generation hardware they power also still relatively crude. But rudimentary quantum computers already now exist. And they are already being used by companies.

Volkswagen has used algorithms powered by quantum computers to research battery technology for electric vehicles. Amazon and Microsoft have started integrating quantum computing tech into their cloud data centres for specialist use cases. And RBS has also made use of 1Qbit’s technology to trial quantum computing modelling of how much capital it should set aside for bad loans.

Stewart reports that calculations that would normally take weeks were completed “in seconds, and provided a better answer”.

While the technology is still in its early days and qubits created by quantum engineers unstable and fragile, early systems have already demonstrated how powerful a tool they will be when it comes to simulating complex systems and conducting virtual experiments. Huge volumes of data can be processed by algorithms almost instantly.

The pharmaceuticals industry has been an early adopter and the potential of quantum computing to transform medicine could see some almost unimaginable breakthroughs in treatments over the next couple of decades.

As the 39-year-old Fursman puts it:

“If you could do more work in a single day than has ever been done before in the history of humanity, you can only imagine the things that you would discover, the materials that would be possible . . . real opportunities to, quote unquote, change everything.”

One fear attached to quantum computing is that its emergence will render current cybersecurity technology obsolete overnight. Hackers with access to quantum computing resources would be expected to be able to walk through digital security at the world’s largest companies, financial institutions, government agencies and militaries at will.

For RBS, its investment in 1Qbit is an insurance policy against being caught off guard by the emergence of the ‘true’ quantum computing age in several years. Stewart also believes it means the bank is “18-24 months” ahead of rivals when it comes to its understanding and ability to integrate the technology.

Fursman also think’s the bank’s investment in his company is a win-win:

“Maybe a million-dollar investment in order to understand something that could jeopardise your multibillion-dollar business is a great trade-off at this stage”.