Physicists have made it 72 times faster to boot up quantum computers

Scientists normally spend six hours booting up quantum computers each day, but a new algorithm has cut the process down to just five minutes.

Image: Erik Lucero/UCSB

Quantum computers have the potential to revolutionise the way we analyse and store data, but they're also extremely sensitive. 

Even when working with a chip with just five quantum bits or 'qubits' on it, scientists need to spend hours each day calibrating and setting up the chip so that it functions properly. This is because quantum computers are extremely sensitive to tiny changes in the local environment, such as temperature, humidity and air pressure. If it's slightly warmer one day than the day before, the computer has to be completely recalibrated.

To do this, quantum physicists sit down each day and see how conditions have changed slightly from the day before. They then recalibrate the chip accordingly, and only a 0.1 percent error rate is allowable when measuring the ambient conditions. If the measurements are further out than that, the quantum computer won't work. To put it another way, just one in a thousand measurements can be slightly off for the computer to boot up, and each time around 50 different parameters need to be measured and compared to the day before. 

But now, a researcher from Saarland University in Germany has reworked the whole rebooting process. 

"We asked ourselves the question: Why is it necessary each and every day to understand how conditions differ from those of the day before?' The answer we eventually came up with was that it isn't necessary," said Professor Frank Wilhelm-Mauch, leader of the project, in a press release. "What's important is that the setup procedure produces the right results. Why it produces the right results is not so relevant."

Instead, the team came up with another algorithm that reduced the error rate to below 0.1 percent and sped the time up from six hours to five minutes. Even more importantly, the calibrations are done automatically.

"For the calibration procedure we used an algorithm from engineering mathematics, strictly speaking from the field of civil and structural engineering, as that's another area in which experiments are costly," explained Professor Wilhelm-Mauch.

The methodology has now been rigorously tested and proved by physicists from the University of California in Santa Barbara. The Saarbrücken methodology as its called, is known as Ad-HOC (Adaptive Hybrid Optimal Control). The research has been published in Physical Review Letters.

The research means that experimental quantum physicists now just have to push a button and then go and get a coffee for five minutes before they can use the quantum computing system for a day of research - in the past by the time system was booted up there were only a few hours left for experiments.