New Theory May Solve Quantum ‘Jigsaw Puzzle’
August 08, 2025 -- In the past, chemists have used temperature, pressure, light, and other chemical ways to speed up or slow down chemical reactions.
Now, researchers at the University of Rochester have developed a theory that explains a different way to control chemical reactions—one that doesn’t rely on heat or light but instead on the quantum environment surrounding the molecules.
In a paper published in the Journal of the American Chemical Society, the researchers—including Frank Huo, the Dean and Laura Marvin Endowed Professor in Physical Chemistry in Rochester’s Department of Chemistry and graduate students Sebastian Montillo and Wenxiang Ying—argue that traditional theories used to predict how fast chemical reactions occur may not fully capture what happens under certain quantum light-matter interaction conditions. To address this, they developed a new theory showing how quantum effects—specifically, an effect called vibrational strong coupling (VSC)—can influence chemical reactions.
This phenomenon has been observed in experiments, but the new theory helps clarify how it works and could pave the way for more precise, energy-efficient chemical processes, with potential applications in manufacturing, medicine, and advanced materials.
“Our work may provide the first-ever theory that describes the experimentally observed phenomena,” Huo says. “It tells us that the quantum environment alone can influence chemistry in ways we didn’t think were possible and opens the door for new materials and technologies.”
Solving a quantum chemistry puzzle
In 2016, a group of scientists discovered something surprising: They were able to change how fast a chemical reaction occurs by putting the reacting molecules in a tiny space between two gold mirrors, only millionths of a meter apart. This created an environment—called an optical microcavity—where the quantum energy and electromagnetic fields in the space itself could couple with the natural vibrations of the molecules and slow down or speed up the chemical reactions between the molecules. The effect is called vibrational strong coupling.
Since then, VSC has baffled researchers.
For the past five years, Huo and his colleagues have been developing a theory that explains the phenomenon so that VSC can be understood, utilized, and controlled. Using computer simulations and quantum mechanics principles, they developed their new theory, which explains why the VSC effect happens or doesn’t happen, how changing the strength of the interaction changes the speed of the reaction, and what it could mean for the future of chemistry.
“This was like solving a challenging jigsaw puzzle, where all of the puzzling features of VSC finally fit neatly together,” Huo says. “This new strategy of VSC can selectively slow down or speed up a reaction, offering a paradigm shift in synthetic chemistry that could significantly impact drug development and materials synthesis.”
The Air Force Office of Scientific Research and the National Science Foundation supported this research.