Fig. 2: Robust two-peak deep-lying excitonic structure across bulk and monolayer.
From: Real- and momentum-space description of the excitons in bulk and monolayer chromium tri-halides
The low-energy (0−2 eV) part of imaginary part of macroscopic dielectric response Imϵxx with the perturbing electric field applied along the (100) direction of the material, for bulk and free-standing monolayers of CrX3 with (a) X = Cl, (b) X = Br, (c) X = I. Optical broadening of 2 milli-Hartree is used at all energies. The intensities of the peaks are multiplied by some constant factors to bring them to the same scale.
