Chinese scientists achieve breakthrough, detect rare quantum friction in folded graphene
Friction, though familiar in everyday life, remains a complex phenomenon—especially at the microscopic level. Scientists long believed it arose from rough surfaces rubbing together, where tiny bumps and sticky spots resisted motion and transformed energy into heat.
As experimental tools advance, scientists are pushing beyond classical friction laws to investigate friction at the atomic scale.
In a recent study, a Chinese team from the Lanzhou Institute of Chemical Physics, led by Professor Zhang Junyan and Associate Professor Gong Zhenbin, used precise nanomanipulation to create folded graphene edges with controlled curvature and layer numbers, enabling detailed measurements of friction at the nanoscale.
Their findings revealed that friction at the folded edges of graphene does not follow a linear pattern as layer numbers increase. Instead, it changes in a highly nonlinear fashion—raising fundamental questions about the limits of classical friction models when applied to solid-solid quantum interfaces.
Folding graphene to test limits of friction at the quantum scale
A surprising discovery in 2022 revealed that water flows faster through narrower carbon nanotubes—reversing what we see in everyday plumbing. Researchers linked this counterintuitive behavior to quantum friction, where fewer electrons in narrower tubes reduce resistance to flow, the South China Morning Post reported.
Inspired by those findings, the Chinese scientists developed an approach which allowed them to probe the elusive effects of quantum friction at solid interfaces with unprecedented control. As the researchers increased the number of graphene layers in each fold, friction behaved unexpectedly—varying in surprising ways and sometimes even decreasing with added thickness.
According to the research team, this marks the first experimental evidence of quantum friction occurring between two solid surfaces. They emphasized the significance of the discovery in a social media post, highlighting its potential impact on future technologies.
New way to reduce friction
By folding the graphene, the researchers induced internal strain that altered how electrons moved through the material. This strain forced the electrons into fixed energy states, known as pseudo-Landau levels, which reduced energy loss as heat and ultimately lowered the friction at the interface.
The researchers conducted their experiment using a carefully engineered graphene system cooled to ultra-low temperatures. Looking ahead, they plan to explore whether the same quantum friction effects can be observed in other materials and under conditions more relevant to real-world applications.
Exploring quantum friction across a wider range of materials and temperature conditions, the researchers noted, could provide deeper insights into how energy is dissipated at the atomic level.
In the long term, as the scientists note, this understanding may pave the way for technologies that actively manage or even minimize energy loss in practical devices, from nanoscale electronics to quantum computing systems.
Their study can be found in the journal Nature Communications.
