HR-EELS is a powerful tool to probe any kind of excitations that emerge in a solid crystal such as plasmon, phonon, inter- & intra-band transition, and local vibrations. HR-EELS technique makes use of inelastic scattering of incident electrons with an energy of 5 ~ 200 eV with an optimal energy resolution of less than 0.5 meV, which exchange energy with the excitations.

Recent HR-EELS studies focusses on low-dimensional (1D) collective excitations, such as two-dimensional (2D) collective excitations of Dirac fermions, charge excitations in quasi-one-dimensional atomic chain, and topological properties of phonons.