Riverlane now shipping second generation quantum products, says founder

Riverlane’s founder and CEO Steve Brierley was recently awarded an OBE. To mark the occasion, it was an honour to have been invited in to discuss the progress being made in the quantum computing sector.

Although quantum computers are a few years off being commercially viable, the race is on – and Riverlane’s technology is already a crucial part of the mix.

Riverlane, which was founded in 2016, is based at St Andrew’s House – the same location as the last interview I had with Dr Brierley, in 2019. So I asked him what had changed since we last met?

“The big news is that there’s an ecosystem-wide recognition that quantum error correction is the big challenge,” he replied. “There’s new evidence that without error correction you can’t do anything commercial – in other words commercial applications of quantum computing will require error correction.”

Does everybody accept that?

“Yes. It’s something we’ve been saying for a long time and it’s now broadly accepted in the ecosystem.”

Are you well set up for this new era?

“Yes, this is an absolutely amazing time for us. As a company we’re in the right place at the right time, solving a central challenge, and suddenly everybody is trying to work out how they can solve error correction, so they need our technology.”

Current error correction is effective for one in 100 calculations, but Riverlane’s technology is looking to reduce that to one in a trillion. Have you closed that gap?

“Yes. We take error-prone qubits [the basic unit of information in quantum computing] and we arrange them into logical blocks that are then protected against errors. So we make reliable computers out of unreliable components.”

Are they your computers?

“No. So we work with different companies that are building quantum computers, such as Rigetti and Oxford Quantum Circuits. We design chips that correct errors in [their] quantum computers. We have chip design capability and quantum error expertise. Just as AI needed CPUs to scale, to scale quantum computers you’re going to need our chips. We’re now shipping second generation products to hardware companies like Oxford Quantum Circuits – I guess it’s a good Cambridge/Oxford success story.”

And will there be a standard quantum hardware format soon?

“I don’t know. It’s really unclear which qubit technology will ultimately be the right approach, and I even wonder if it’s likely to be multiple approaches.

“There’s four or five different types of physics to build a qubit that have all made progress in the last few years. That’s a 20-year trend now and that’s really why the ecosystem has shifted to work on error correction – the qubits are good enough that we can work on error correction.”

Dr Brierley founded the company in 2016 and has overseen Riverlane’s trajectory, including heading a consortium to build a quantum operating system, and a £15m Series B fundraise last year. This year he was awarded an OBE – congratulations.

“Thank you – and for quantum computing!”

A first?

“I think so. You see that for physics or education, but for quantum computing….”

Have you collected it?

“Not yet. I have a very nice letter. I’m waiting for the ceremony, I think it’s in Westminster.”

You’re also advising the government as well?

“Yes, there was a Select Committee meeting just last week I gave evidence at. To me the important thing is for government to act as an intelligent customer in the space. I think quantum computing is as important as the semiconductor industry and the UK absolutely needs to have a leading role in that.

“The UK shouldn’t expect that we would end-to-end develop all of the quantum computing supply chain. As that supply chain emerges I think the UK needs to be smarter, where it’s essentially backing a race at least – not necessarily a winner, but a part of the supply chain that it thinks it can realistically win.

“The UK has quite a few strengths actually. One really interesting one is in photonics. The photonics industry is as big as the pharmaceutical sector and it’s overlooked, probably because in the pharmaceutical sector there’s a small number of large companies, but the photonics industry is some six or seven thousand companies, largely based around Glasgow. It grows at an impressive rate year-on-year. That’s an important adjacent technology for quantum computing. The UK has the chip design and the quantum computing expertise – that’s a really unique combination.”

How do you see quantum technology evolving in Cambridge?

“We’re strong in chip design, that’s why Riverlane is based here in Cambridge. There’s a massive talent pool to address many of the engineering challenges in quantum computing. Perhaps it’s not obvious they can contribute to quantum computing but actually we need those engineering skills. For example, our chips will be processing in the order of 100 terabytes per second, which is about the scale of Netflix’s global streaming. This has only been done before at places like CERN and we need this chip designing expertise to solve this scale of engineering problem.”

Is that happening here?

“Yes. In this building. The whole system, which we call Deltaflow, is comprised of the decoder chip, which is the brains of the whole system; there’s a data movement component which takes the data from the quantum computer and brings it to the right place at the right time, and there’s a software stack which makes it easy to programme the system.

“We do the design here and it’s taped out by a fabrication partner in the US. We’ve also got a lab here where it’s tested out.”

Riverlane has a team of 90 people at St Andrew’s House, with 10 more in the US – “also in Cambridge, Cambridge Massachusetts, a customer success team”.

So what’s the next step?

“The key thing for us is the next-generation chip – that will support logic in the quantum computer.

“We’ve done the first step in our roadmap, which was to correct errors very quickly – which essentially keeps the qubit alive for a very long time, like a memory – but you want to do operations on your computer, so the next step is to implement logic, and that’s a more complex problem, so it needs the next-generation chip design.”

Will there be a tipping point, as is happening with AI?

“It’s going to happen in the next three years. It’s the point at which a quantum computer can no longer be simulated – as in, it goes beyond the capability of any supercomputer. You could simulate the current quantum computer with your laptop, so there’s no need to necessarily buy one. But in the next three years, with our error correction stack, and the progress that our customers have made on the underlying qubits, you’ll be able to go beyond that supercomputing frontier, so that’s a hugely exciting inflection point for the whole field.

“Interestingly, it’s the mission that the UK government has said ‘we’ve got a £2.5bn strategy over the next 10 years and what we want from that money is to get to one million error-free operations by 2028’ – that’s the first milestone beyond supercomputing.

“The ultimate goal is one in a trillion error-free calculations. It’s a sliding scale.”

What sort of functionality will that offer?

“It’s a new type of computer. Some of the use cases we know already are around understanding the foundations of physics, understanding material sciences, understanding chemistry and ultimately the applications are using computers to design products in industries we can’t currently because the underlying physics is so complicated.

“So it would be in healthcare, how a protein interacts with an organic molecule, it could be in a new catalyst to reduce the CO2 emissions in an industrial process, or to extract CO2 from the atmosphere to address climate change – there are a huge number of societal benefits if we can build an error-corrected quantum computer.

“We will supply the error-correction stack – that’s the chip and our software, to companies building the rest of the system. They’ll be system-integrated. It’s perhaps more like NVIDIA, in that NVIDIA builds the chips and the software and ships a complete product, than Arm.”

And are you agnostic about what systems you supply?

“Yes, we work right across the different technologies.”