While some might consider games entertainment, Prof. Emanuele Dalla Torre from Bar-Ilan University in Israel and the rest of his team believe that games are a useful tool for measuring the effectiveness of commercial quantum computers.
A recent study in Advanced Quantum Technologies describes how Dalla Torre and his two students, Meron Sheffer, and Daniel Azses ran a mathematical collaboration on various technologies to determine 1) whether they had quantum mechanical properties and 2) whether the machines produced correct results. The results were then compared to classical computers.
Only the Quantinuum Model H1-1, powered by Honeywell, outperformed the other technologies. Dalla Torre stated that classical computers only return the correct answer 87.5 per cent of the time. The H1-1 returned the correct answer 97% of the time. (The game was also tested on the now-retired System Model H0 which returned a score of 85 per cent.
The H1 shows a probability of not 100%, so it’s not perfect, but it’s still well above the classical threshold. Dalla Torre stated that it behaves quantum mechanically.
The game is fun
Nonlocal correlations are required for the mathematical game Dalla Torre played with his team. It’s a game that requires collaboration; in other words, parts of the system cannot communicate with each other to solve problems or score points.
Dalla Torre said that it’s a cooperative game based on mathematical rules. Players score points if they satisfy all of these rules.” The key problem is that the players can’t communicate during the game. It would be simple if they could communicate – but it isn’t. Imagine building something and not being able to communicate with each other. There is a limit to how much you can build. This is the classic threshold for machines in this game.
Because quantum computers follow quantum mechanical properties that allow for nonlocal effects, they are uniquely equipped to solve these problems. Quantum mechanics states that something can instantly affect another thing that’s in the same place.
Dalla Torre stated that the experiment shows that there is a nonlocal effect. This means that when you measure one qubit, it affects all the qubits simultaneously.
Performance is better with less noise.
Dalla Torre attributes Quantinuum’s performance to its low level of noise.
Today’s commercial quantum computers are subject to noise and interference from many sources. It is necessary to suppress or eliminate such noise to scale the technology and achieve fault-tolerant systems (a design principle that prevents errors cascading through a system and corrupting circuits).
Dalla Torre stated that noise in this context means an imperfection; it’s just like a typo. IQS is noisy intermediate scale quantum computing. This is the general term for all devices we currently have. These devices are quantum but not perfect. They do make mistakes.
Quantinuum’s Commercial Operations Group Leader, Dr Brian Neyenhuis, believes projects like Dalla Torre are important benchmarks for early quantum computers. They also help to demonstrate and better understand the differences between quantum and classical computation.
After seeing the initial results of the H0 system, he collaborated with Dalla Torre to run it again using the upgraded H1 system (still using six qubits).
Dr Neyenhuis stated that although we knew that the H1 system was a significant step forward, it was still a nice signal that the improvements directly translated into better performance on the nonlocal game.
Next steps
Dalla Torre, his students and the Microsoft Azure Quantum platform completed the experiment. He stated that it was vital to quantum experimentation’s growth that this work could be done on the cloud. “It was amazing to connect to computers from Israel, Bar-Ilan University, and I could do so using the internet.
Dalla Torre and his group would like to continue this research, particularly as commercial quantum computers increase qubits and reduce noise.
