Interlayer Electron-Phonon Interaction and Phonon Chirality at Two-Dimensional Material/Silicon Dioxide Interface

In this work, we report the emerging phonon emissions arising from the strong electron-phonon interaction at the few-layer two-dimensional (2D) material/silicon dioxide (SiO₂) interfaces. The new phonon modes, which are originally Raman silent, are robust at the interfaces with various 2D materials coupled to the surface of SiO₂. We demonstrate that through electron-phonon coupling, the intrinsic properties of the electronic band structures in the coupled 2D materials are revealed by the novel chirality and in-plane anisotropy of the phonon modes. Our observations provide a deep insight into the microscopic mechanism of electron-phonon interaction at the interfaces between 2D materials and dielectrics.