Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride
Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride
We demonstrate that the valence energy-loss function of hexagonal boron nitride (hBN) displays a strong anisotropy in shape, excitation energy and dispersion for momentum transfer q parallel or perpendicular to the hBN layers. This is manifested by e.g. an energy shift of 0.7 eV that cannot be captured by single-particle …