Quantum computer reveals chemical reaction in 100-billionth-speed slow-mo

Quantum computers can handle calculations that are well out of the reach of traditional computers, and now scientists in Australia have used the tech to observe something usually too fast for the eye to see. The team managed to slow down a molecular interaction by 100 billion times to see what’s really going on in a common chemical reaction.

The microscopic world of atoms and molecules is incredibly tricky to study, not just because everything is so small but because it all happens much faster than our eyes can register. Chemical bonds, for instance, can form and break on a scale of femtoseconds – quadrillionths of a second. That makes it difficult to understand exactly what’s happening during some key processes.

For the new study, researchers at the University of Sydney used a quantum computer to slow down one of these super-fast processes. They witnessed what happens to a single atom when it encounters a geometric structure called a conical intersection, which are common in chemical reactions like photosynthesis. Scientists have been trying to directly observe these processes for decades.

Using a trapped-ion quantum computer, the team mapped the problem onto a fairly small quantum device, which allowed them to slow down the process by an astonishing 100 billion times. That brought it down to the kinds of speeds existing technology can observe and measure.

“In nature, the whole process is over within femtoseconds,” said Vanessa Olaya Agudelo, co-lead author of the study. “Using our quantum computer, we built a system that allowed us to slow down the chemical dynamics from femtoseconds to milliseconds. This allowed us to make meaningful observations and measurements. This has never been done before.”

Though it might sound like a mere simulation, the team says it’s closer to a controlled-environment experiment, in the same vein as a wind tunnel for observing airflow dynamics for aircraft.

“Our experiment wasn’t a digital approximation of the process – this was a direct analogue observation of the quantum dynamics unfolding at a speed we could observe,” said Dr. Christophe Valahu, co-lead author of the study.

Using quantum computers for these kinds of experiments could help scientists better understand the fast-paced world of molecular interactions, which could in turn inform advances in a range of fields.

“It is by understanding these basic processes inside and between molecules that we can open up a new world of possibilities in materials science, drug design, or solar energy harvesting,” said Olaya Agudelo. “It could also help improve other processes that rely on molecules interacting with light, such as how smog is created or how the ozone layer is damaged.”

The research was published in the journal Nature Chemistry. The team describes the work in the video below.

Source: University of Sydney