Integrated quantum computing company Quantinuum has announced a major milestone in its development of quantum hardware, achieving what it says is the first five-digit score on the globally recognised Quantum Volume benchmark. Its H1-1 quantum processor reached a score of 16,384, and then 32,768 in subsequent tests. This beat its previous record-breaking score of 8,192 by some margin.
IBM introduced the concept of quantum volume in 2017 as a way to provide a more comprehensive and realistic measure of the performance of quantum computers as pure qubits didn’t paint a full and true picture due to the different types of quantum computing systems at play.
Quantinuum, formed from the spin-out of Honeywell Quantum Solutions and its merger with Cambridge Quantum in June 2021, says it has always focused on quantum volume as it provides a useful measure to judge performance against. The company has now set a new industry benchmark eight times in the past three years for this metric.
Its H1-1 quantum computer has 20 fully connected qubits and five gate zones to allow for more simultaneous quantum operations, this was last upgraded in 2022 and has contributed to the increase in quantum volume. The computer is based on quantum charge coupled device technology, a solid-state device that consists of a two-dimensional array of qubits that are arranged in a similar way to the pixels in a CCD.
To achieve the increased performance the company also confirmed it achieved reductions in the phase noise of the device’s lasers, reducing two-qubit gate error and memory error, and improvements to elements of the calibration process. These improvements, according to scientists at Quantinuum, allowed for faster algorithm runtimes, improved the ability to run quantum error correction and better results for those using the hardware to run algorithms.
Improvement in error correction
Dr Brian Neyenhuis, director of commercial operations at Quantinuum, credits reductions in the phase noise of the computer’s lasers as one key factor in the increase. “We’ve had enough qubits for a while, but we’ve been continually pushing on reducing the error in our quantum operations, specifically the two-qubit gate error, to allow us to do these quantum volume measurements,” he says.
The Quantinuum team says it has improved memory error and elements of the calibration process as well. “It was a lot of little things that got us to the point where our two-qubit gate error and our memory error are both low enough that we can pass these quantum volume circuit tests,” Neyenhuis adds.
Having a five-digit quantum volume number is an important milestone when it comes to real-time quantum error, a critical ingredient to large-scale quantum computing. “The sooner it can be explored on today’s hardware, the faster it can be demonstrated,” the company wrote.
“With the technology improving fast, we do everything we can to help our customers and the community understand how we are achieving such rapid progress,” said Jenni Strabley, senior director of offering management at Quantinuum. “Which is why we have published the data behind the results we announced today. Our goal is to accelerate quantum computing, and that is something we can only achieve as an industry.”
Paul Smith-Goodson, analyst at Moor Insights and Strategy said quantum volume is a crucial measurement in the ongoing research and development necessary to drive quantum computing forward, and eventually achieve quantum advantage. “Quantinuum has prioritised increasing its quantum volume since the start, which has not only benefitted its current applications but set itself up to be the benchmark in achieving quantum advantage,” Smith-Goodson says.
Read more: Could quantum computing make our energy grid sustainable?
