Researchers from China's Lanzhou Institute of Chemical Physics (Chinese Academy of Sciences) have observed the quantum friction phenomenon at solid-solid interfaces for the first time, making a significant breakthrough in quantum friction research. By folding graphene sheets, the researchers induced internal strain that altered how electrons moved through the material.
The nature and mechanism of friction are seen as core scientific questions - 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. The researchers utilized nanomanipulation techniques to construct folded graphene edge topological structures with controllable curvature and layer numbers. Systematic measurements of nanoscale friction were conducted.
The results showed that the frictional force at the edges of folded graphene exhibits significant nonlinear variations with respect to the number of layers, challenging the applicability of classical friction laws at solid-solid interfaces.
Through meticulous experimentation and theoretical analysis, the team uncovered the microscopic mechanism: non-uniform strain in the folded graphene induces a special magnetic field effect, leading to changes in its electronic structure.
This alteration in electronic structure suppresses the energy dissipation process, transforming energy dissipation from a continuous mode to a quantum leap mode. It also prolongs the cooling time of hot electrons, thereby effectively reducing friction.
The research provides the first experimental evidence for quantum friction at solid-solid interfaces. It establishes a new research framework for regulating energy dissipation based on topological structures and demonstrates the feasibility of controlling interfacial friction through quantum states, the team said.
The study holds significance for developing low-energy-consumption nanodevices and regulating friction in topological quantum materials.
