Quantum computers are promised as the beginning of a new technological era, in which processing huge amounts of data, which even for the best classic supercomputers today are a titanic task, will be a job for them that will be solved in minutes, even seconds. Thanks to its power, sites as remote as cybersecurity or medicine will move to another level. However, today’s quantum machines are still imperfect and there is time for us to enjoy their full potential. However, applications, although very specific, are already developing.

This is the case of the experiment conducted by researchers from the University of Sydney (Australia), who for the first time have used a quantum computer to directly design and observe a critical process in chemical reactions slowing it down by 100,000 million times. Conclusions have just been published in a study in Nature Chemistry.

“By understanding these basic processes within and between molecules we can open up a new world of possibilities in materials science, drug design or solar energy collection,” explains Vanessa Olaya Agudelo, the first author of the article. “It could also help to improve other processes that depend on molecules that interact with light, such as how smog is created (the low, very polluting cloud formed by carbon dioxide, hollines, smoke and dust that forms on large cities or industrial cores) or how the ozone layer is damaged.”

Processes that last less than one blink

Specifically, the team witnessed the interference pattern of a single atom caused by a common chemical geometrical structure called the conical intersection. Conical intersections are vital for rapid photochemical processes, such as capturing light in human vision or photosynthesis. Chemists have tried to directly observe these processes since the 1950s, but it is not feasible to observe them directly given the extremely rapid time scales that occur; they occur in a matter of femtoseconds, which is equivalent to the millionth part of a second.

To solve this problem, researchers created an experiment using a quantum computer of ions trapped in a completely new way. “Using our quantum computer, we built a system that allowed us to slow down the chemical dynamics of femtoseconds to milliseconds. This allowed us to make significant observations and measurements,” says Olaya Agudelo. “This has never been done before.”

For his part, Christophe Valahu, another author explains that, until now, the process had not been directly observed. "It happens too quickly to investigate experimentally," he said. Using quantum technologies, we've tackled this problem."

Valahu compares the process by simulating the air patterns around the wing of an aircraft in a wind tunnel. “Our experiment was not a digital approximation of the process, but a direct analogue observation of the quantum dynamics that develops at a speed we could observe,” he says. I mean, it's not a computer-created model, but you've been able to see the actual process.

In photochemical reactions like photosynthesis, through which plants get their energy from the Sun, molecules transfer energy at lightning speed, forming areas of exchange known as conical intersections. This study slowed down dynamics in quantum computers and revealed predicted revealing features, but never seen before, associated with conical intersections in photochemistry.

The experiment not only helps to better understand chemical processes that last less than a blink, but also opens the door to new tests combining chemistry and physics with quantum computers. In the words of Tadmii Tan, head of the team that was used for the experiment: "This is a fantastic collaboration between chemical theorists and experimental quantum physicists. We are using a new approach in physics to address a long-standing problem in chemistry."