Helium diffraction on SiC grown graphene: Qualitative and quantitative descriptions with the hard-corrugated-wall model

Monolayer epitaxial graphene grown on 6H-SiC(0001) was recently investigated by grazing-incidence fastatom diffraction and analyzed with an ab initio electronic density calculation and with exact atomic diffraction methods. With these results as a reference, the hard-corrugated-wall model (HCW) is used as a complementary analytic approach to link binary potentials to the observed atomic corrugation. The main result is that the HCW model reproduces the macroscopic corrugation of the moir pattern on a quantitative level, suggesting that soft-wall corrections may be neglected for macroscopic superstructures, allowing straightforward analysis in terms of a one-dimensional corrugation function.