The understanding of interactions between electrons and phonons in atomically thin heterostructures is crucial for the engineering of novel two-dimensional devices. Electron–phonon (el–ph) interactions in layered materials can occur involving electrons in the same layer or in different layers. Here we report on the possibility of distinguishing intralayer and interlayer el–ph interactions in samples of twisted bilayer graphene and of probing the intralayer process in graphene/h-BN by using Raman spectroscopy. In the intralayer process, the el–ph scattering occurs in a single graphene layer and the other layer (graphene or h-BN) imposes a periodic potential that backscatters the excited electron, whereas for the interlayer process the el–ph scattering occurs between states in the Dirac cones of adjacent graphene layers. Our methodology of using Raman spectroscopy to probe different types of el–ph interactions can be extended to study any kind of graphene-based heterostructure.

We studied the polarization dependence of the resonance Raman spectra for several different isolated single-wall carbon nanotubes (SWNTs). One isolated SWNT acts as a dipolar antenna, polarized along the tube axis. For light polarized parallel to the tube axis, the strong resonance-effect breaks the symmetry-selection rules, and symmetry-forbidden modes appear in the Raman spectrum. When the light is not polarized parallel to the tube axis, G-band mode symmetries can be identified. Unusual G-mode intensity behavior is observed when the Raman signal is obtained from more than one SWNT, suggesting a complex multipolar antenna pattern.