Understanding how atoms move across metal surfaces is critical for improving technologies that store and generate energy, like batteries, fuel cells, and industrial catalysts.
These tiny motions help determine how materials degrade, how fast chemical reactions occur, and how efficiently energy is transferred.
But simulating atomic motion accurately isn’t as simple as it sounds—especially when quantum physics comes into play.
Atoms are made up of a dense nucleus and much lighter electrons.
Because electrons are so light—nearly 2,000 times lighter than even the smallest atomic nucleus—they tend to respond almost instantly when the nucleus moves.
This means scientists often simplify their calculations by assuming electrons always keep up with the nuclei, a trick known as the “adiabatic approximation.”
However, this shortcut doesn’t always work. On metal surfaces, the interaction between electrons and atomic nuclei can be much more complex.
In these situations, electrons can’t instantly adjust to nuclear motion, and this interaction becomes important. One major effect is known as “electronic friction.”
It’s like a drag force caused by electrons that slows down atoms moving across a metallic surface. This influences how atoms stick, vibrate, and spread across metals.
Now here’s where things get really tricky. Atomic nuclei don’t behave like balls rolling on a surface. They’re quantum particles. They have a type of built-in motion called zero-point energy, which means they’re never completely at rest.
They can even “tunnel” through barriers, escaping areas they wouldn’t be able to in classical physics. These quantum behaviors can significantly change how chemical reactions unfold—and they’re extremely difficult to model.
In a new study published in Physical Review Letters, scientists George Trenins and Mariana Rossi found a way to bring together electronic friction and the complex quantum behavior of atomic nuclei.
They used a powerful method from quantum mechanics called the path-integral formulation. This technique allows researchers to simulate not only where atoms are, but also how their past motion affects their present behavior—something called “memory.”
By including both memory effects and quantum properties like zero-point energy, their method could finally explain a strange match between previous simplified models and real experimental results. Their work helps us understand how energy is exchanged at the surface of metals and could lead to better materials for technologies like single-atom catalysts or two-dimensional materials used in electronics and clean energy.
Trenins explains that the goal is to get the correct physical picture, not just the right numbers. Rossi adds that this new method opens the door to exploring far more complex systems than ever before.
With this breakthrough, we’re one step closer to unlocking the hidden world of quantum motion on metal surfaces.
