The reporter learned on the 14th that scientific researchers from the Institute of Physics of the Chinese Academy of Sciences, the National Center for Nanoscience and other units found that there is a strong interaction between electrons and infrared phonons in the diamond stacked three-layer graphene, which is expected to be used in fields such as photoelectric modulators and photoelectric chips. The relevant research results are published online in the journal Nature Communications. In recent years, three-layer graphene has attracted widespread attention from researchers. Usually, three-layer graphene can exhibit two different stacking geometries, namely diamond stacking and Bernal stacking. "These two kinds of stacked three-layer graphene have completely different symmetry and electronic properties, such as the center symmetric diamond stacked three-layer graphene has an adjustable energy gap for the displacement electric field, and can show a series of related physical effects that Bernal stacked three-layer graphene does not have: Mott insulation, superconductivity, ferromagnetism, etc." said Zhang Guangyu, the co corresponding author of the paper and a researcher at the Institute of Physics of the Chinese Academy of Sciences. How to understand these unique associated physical effects in three-layer graphene diamond stacks has become one of the important research frontiers. This time, researchers discovered strong interactions between electrons and infrared phonons in diamond stacked three-layer graphene through Raman spectroscopy with adjustable gate voltage and near-field infrared spectroscopy with excitation frequency dependence. "We propose a simple, non-destructive, and high spatial resolution near-field optical imaging technique that can not only identify the stacking order of graphene, but also explore electron phonon strong interactions, providing a solid foundation for future research on multi-layer graphene and corner graphene," said Dai Qing, co-author of the paper and researcher at the National Center for Nanoscience. It is reported that this study provides a new perspective for understanding the physical effects of superconductivity and ferromagnetism in three-layer graphene stacked in diamond shapes. At the same time, it also provides a basis for material research for the design of new generation optoelectronic modulators and optoelectronic chips. (Lai Xin She)