Recently, a research team, jointly headed by Professor Tan Pingheng from the Institute of Semiconductors at the Chinese Academy of Sciences and Professor Ren Bin from Xiamen University, has achieved remarkable strides in investigating the physical attributes of two-dimensional (2D) materials. They ingeniously crafted a versatile plasmon-enhanced Raman spectroscopy technique. This technique effectively activates vibration signals in 2D materials that were previously challenging to detect, owing to weak electron-phonon coupling or Raman-forbidden transitions.

This breakthrough paves the way for a novel research tool, enabling in-depth exploration of the microscopic mechanisms underlying interlayer coupling in 2D materials and their composite structures. The technique harnesses the confinement and enhancement effects of metal nanocavities on the optical field, facilitating high-sensitivity detection of interlayer breathing modes in composite systems consisting of gold/silver nanocavities and 2D materials.

Notably, the study also unveiled, for the first time, that plasmons can modulate the polarization characteristics of vibrational modes, thereby transcending the constraints of traditional Raman selection rules. Furthermore, the team developed an electric field-modulated interlayer bond polarizability model, offering a theoretical explanation for the physical mechanism of signal enhancement and providing robust theoretical backing for experimental observations.

This accomplishment not only signifies a new era in the detection of interlayer phonons in 2D materials but also furnishes fresh characterization concepts and experimental underpinnings for the design of future high-performance optoelectronic devices. The pertinent research findings have been published in the esteemed journal Light: Science & Applications.