British quantum engineering startup Riverlane Ltd. said today it has closed on a £15 million ($18.65 million) round of funding.

The Series B round, which significantly boosts its valuation, will enable it to continue innovating until it becomes cash flow positive, the company said. Molten Ventures led the round, which also saw participation from Altair Engineering Inc., Cambridge Innovation Capital, Amadeus Capital Partners and the U.K.’s National Security Strategic Investment Fund.

Riverlane says it’s building an error-correction system for quantum computers, which rely on quantum physics to process calculations and have the potential to be exponentially more powerful than traditional computers. Quantum computers already exist, but one of the problems in scaling them to a degree that makes them more useful than their classical cousins is the sensitive nature of the quantum bits, or “qubits,” that powers these next-generation machines.

Quantum errors can be caused by many things, including imperfect control signals, interference from the environment and unwanted interactions between one another. They cause what’s known as “noise” that leads to significant errors in quantum calculations. What’s more, the risk of errors grows as more qubits are added to a quantum computer, complicating efforts to make truly game-changing machines.

To fix quantum errors, Riverlane is an operating system called Deltaflow.OS that will be used to control qubits and decode calculations. It was founded in 2016 and currently employs just over 100 staff, with offices in Cambridge, U.K., and the U.S.

In order for quantum computers to be useful in areas such as drug design and material science, they will need to reliably perform trillions of high-speed operations without errors. At present, today’s leading quantum computers can only perform a few hundred quantum operations, or QuOps, per second. Riverlane believes that its Deltaflow.OS software and hardware will enable it to scale quantum machines to around a trillion QuOps per second, which is the number required to execute most quantum algorithms.

Deltaflow.OS incorporates system tools for configuring and tuning the performance of the underlying kernel of quantum computers, as well hardware-based decoders for detecting errors within physical qubits as they occur. It also provides a runtime that orchestrates the operation of these decoders, as well as a control system to implement an error correction cycle. The way it works is, it monitors errors reported by the decoders. Then, it plans the most optimal sequence of operations for the control system to perform in order to recover from those errors.

Riverlane’s roadmap calls for the creation of a chip-based decoder that will be able to process up to 100 terabytes of data per second, by 2025. That’s the equivalent of the same amount of data as Netflix Inc. streams globally.

Riverlane founder and Chief Executive Steve Brierley said the problem of quantum error correction is one of the defining scientific challenges of our time, and is necessary to enable quantum computers to accurately replicate the complexity of nature.

“Armed with useful quantum computers, humans will enter the Quantum Age, where we go from slow trial and error to solve complex problems to an era of rapid design using quantum computers,” he said.

There are many who see great potential in Riverlane’s Deltaflow.OS, including researchers at the University of Wisconsin, Duke University, University of Oxford and University of Innsbruck, home to some of the world’s leading quantum computing research labs. In addition, quantum hardware firms such as Rigetti Computing Inc., Seec Ltd., Universal Quantum Ltd. and Quantum Optics Lab Co. Ltd. are also working with the company.

The money from today’s round will be used to accelerate the development of Deltaflow.OS, the company said.

Molten Ventures Chief Portfolio Officer Stuart Chapman said Riverlane has already made “impressive progress” in quantum error correction. “With Deltaflow.OS in development, Steve and the Riverlane team are ready to bring quantum computing to the commercial world,” he said.

Photo: Riverlane